When to Have Sex to Get Pregnant
The science-backed guide to optimal timing.
The Quick Answer
- Best days: 1-2 days BEFORE ovulation (highest pregnancy rates)
- Fertile window: 5 days before ovulation through ovulation day
- Frequency: Every day or every other day during fertile window
- If you only try once: Day of positive OPK or last day of EWCM
The Fertile Window Explained
You can only get pregnant during a limited window each cycle. This fertile window is determined by two biological facts:
- Sperm can survive: Up to 5 days in fertile cervical mucus (though 2-3 days is more typical)
- The egg survives: Only 12-24 hours after ovulation
This means conception can occur if you have sex anytime from about 5 days before ovulation through the day of ovulation itself. That's your fertile window: approximately 6 days total.
🔬 The Science
The egg can only be fertilized for about 12-24 hours after release. But sperm deposited in fertile cervical mucus can survive and remain capable of fertilization for days while they wait. This is why sex before ovulation is often more effective than sex on ovulation day—the sperm are already in position when the egg arrives.
The Best Days to Have Sex
Research has identified which days within the fertile window give you the highest chances of conception:
| Timing Relative to Ovulation | Chance of Pregnancy* | Assessment |
|---|---|---|
| 5 days before ovulation | ~10% | Possible but low |
| 4 days before ovulation | ~16% | Low-moderate |
| 3 days before ovulation | ~14% | Moderate |
| 2 days before ovulation | ~27% | BEST |
| 1 day before ovulation | ~31% | BEST |
| Day of ovulation | ~20% | Good but timing is tricky |
| 1 day after ovulation | ~0% | Too late (egg is gone) |
*Based on a single act of intercourse. Actual conception rates vary by age and other factors.
🎯 The Takeaway
The 1-2 days before ovulation are your prime time. This is why tracking ovulation is so valuable—you want sperm waiting when the egg arrives, not racing to catch up.
Why Is the Day Before Ovulation Better Than Ovulation Day?
Several reasons:
- Sperm need time to capacitate. Freshly ejaculated sperm need several hours inside the female reproductive tract before they can fertilize an egg. Sperm from the day before have already completed this process.
- The egg's window is short. If you have sex on ovulation day, you might miss the window—the egg may already be declining by the time sperm arrive.
- Timing ovulation exactly is hard. Most tracking methods tell you ovulation is approaching, not that it's happening right now. Sex the day before hedges your bets.
How Often to Have Sex
This is one of the most common TTC questions. Here's what the research shows:
Every Day vs. Every Other Day
Bottom line: Both work equally well for most couples.
| Frequency | Pregnancy Rates | Best For |
|---|---|---|
| Every day | ~37% per cycle | Couples who enjoy it; shorter fertile windows |
| Every other day | ~33% per cycle | Most couples; sustainable; still very effective |
| Once during fertile window | ~15-20% per cycle | Better than nothing, but more is better |
The 4% difference between daily and every-other-day is not statistically significant. Don't stress about having sex every single day if that feels like pressure.
What About "Saving Up" Sperm?
Some people worry that frequent ejaculation depletes sperm. Here's the truth:
- Sperm count does drop slightly with daily ejaculation—but it stays well above the threshold needed for conception
- Old sperm aren't better. After 5-7 days of abstinence, sperm quality actually decreases (more DNA fragmentation)
- Fresh is fine. Daily ejaculation keeps sperm fresh and healthy
⚠️ Exception: Low Sperm Count
If your partner has been diagnosed with low sperm count (oligospermia), your doctor may recommend every-other-day sex to allow sperm counts to replenish between attempts. Follow your doctor's advice in this case.
Our Recommendation
Have sex every 1-2 days during your fertile window. Start when you see fertile cervical mucus or your OPKs start getting darker, and continue through ovulation. This typically means 3-5 days of trying per cycle.
How to Know When You're Fertile
You can't time sex if you don't know when you're fertile. Here are your options:
Option 1: OPKs (Ovulation Predictor Kits)
How it works: Detects LH surge 24-48 hours before ovulation
When to have sex: Day of positive OPK + next 2 days
Pros: Predicts ovulation in advance; clear positive/negative
Cons: Can miss short surges; added daily step
Option 2: Cervical Mucus
How it works: Fertile mucus (egg white consistency) appears before ovulation
When to have sex: All days with watery or egg white mucus
Pros: Free; always available; multiple fertile days
Cons: Takes practice to identify; can be confused with other discharge
Option 3: BBT (Basal Body Temperature)
How it works: Temperature rises after ovulation
When to have sex: Before the temperature shift (combine with other methods)
Pros: Confirms ovulation happened; shows cycle patterns over time
Cons: Only tells you AFTER ovulation; doesn't predict in advance
Option 4: Fertility Monitors
How it works: Tracks multiple hormones (estrogen + LH) for more data
When to have sex: When monitor shows "High" or "Peak" fertility
Pros: More fertile days detected; clear display
Cons: More expensive than basic OPKs
Best Approach: Combine Methods
For the most accurate timing, combine at least two methods:
- EWCM + Positive OPK = Have sex NOW
- BBT confirms ovulation occurred (retroactively)
Easy@Home 50 OPK Strips
Affordable strips that work great for pinpointing your fertile window. Works with the free Premom app for easy tracking.
Common Myths Debunked
❌ Myth: You should have sex ON ovulation day
Truth: Sex 1-2 days BEFORE ovulation has higher success rates. The egg only lives 12-24 hours—sperm that are already waiting have a better chance.
❌ Myth: You need to "save up" sperm
Truth: Frequent ejaculation keeps sperm fresh. Abstaining more than 5-7 days actually reduces sperm quality. Daily sex is fine for most couples.
❌ Myth: Certain positions increase chances
Truth: No research supports any position being more effective. Sperm reach the cervix within seconds of ejaculation regardless of position. Do what's comfortable.
❌ Myth: You should lie down with legs up after sex
Truth: Sperm enter cervical mucus almost immediately—gravity doesn't affect this. Lying down for a few minutes is fine if you like it, but it doesn't change your chances.
❌ Myth: Female orgasm is required for conception
Truth: Nice if it happens, but not necessary for pregnancy. Sperm reach the cervix with or without female orgasm.
❌ Myth: Morning sex is best
Truth: Sperm counts may be slightly higher in the morning, but the difference is negligible. Have sex when it works for your schedule and energy levels.
❌ Myth: Lubricants are fine to use
Truth: Most commercial lubricants (including saliva) can harm sperm motility. Use a fertility-friendly lubricant like Pre-Seed if you need lubrication.
Tips for TTC Sex
Keep It Enjoyable
Timed intercourse can start to feel clinical. Remember why you're doing this—you're creating a family together. Try to maintain intimacy and connection, not just "get it done."
Use Fertility-Friendly Lubricant
If you need lubrication, regular lubricants can harm sperm. Choose one designed for TTC:
Pre-Seed Fertility Lubricant
Mimics fertile cervical mucus. FDA-cleared as sperm-friendly. The #1 choice for TTC couples who need lubricant.
Don't Skip Days at the End
The day of your positive OPK and the day after are crucial. Even if you've had sex earlier in the week, try not to skip these key days.
Communicate with Your Partner
TTC can be stressful. Talk openly about how you're both feeling. If timed sex feels like pressure, consider "covering your bases" with sex every 2-3 days all cycle—no tracking stress, and you'll likely hit your fertile window.
When to Seek Help
If you've been timing sex well and haven't conceived after:
- 12 months of trying (under age 35)
- 6 months of trying (age 35-39)
- 3 months of trying (age 40+)
...it's time to consult a fertility specialist. Good timing helps, but it can't overcome all obstacles.
The Simple Plan
Here's your evidence-based strategy:
- Track your fertile window using OPKs, cervical mucus, or a fertility monitor
- Start having sex when you notice fertile signs (EWCM, darkening OPK)
- Have sex every 1-2 days through ovulation
- Prioritize the day of your positive OPK and the following day
- Keep it fun—stress doesn't help anyone
That's it. No fancy positions, no leg-elevated headstands. Just well-timed sex, with a little patience. Good luck! 🍀