Intercourse After Ovulation and Endometrial Receptivity
Intercourse one day after ovulation does not improve endometrial receptivity or implantation success and is actually too late for optimal conception. The fertile window closes on the day of ovulation, and intercourse after this point has minimal to no benefit for achieving pregnancy.
Timing of the Fertile Window
The evidence is clear that conception requires intercourse before ovulation, not after:
The fertile window spans only 6 days, ending on the day of ovulation itself. Intercourse occurring 1-2 days before ovulation provides the highest probability of conception, as sperm require time to capacitate and position themselves in the fallopian tubes 1, 2.
Nearly all pregnancies result from intercourse during the 6-day period ending on ovulation day. Conception probability ranges from 0.10 when intercourse occurs 5 days before ovulation to 0.33 on the day of ovulation itself 3.
Intercourse after ovulation has essentially zero probability of resulting in conception because the oocyte has already been released and has a very limited lifespan (approximately 12-24 hours) 3.
Peri-Implantation Intercourse Does Not Harm Receptivity
While intercourse after ovulation won't help achieve pregnancy, there is reassuring evidence that it doesn't harm an existing conception:
Intercourse during the implantation window (5-9 days after ovulation) does not reduce fecundability. A large prospective study of 2,606 cycles found no negative effect of peri-implantation intercourse on pregnancy rates (adjusted fecundability ratio: 1.00,95% CI: 0.76-1.13) 4.
Previous concerns about post-ovulatory intercourse interfering with implantation have been disproven by this high-quality evidence 4.
Endometrial Receptivity and the Implantation Window
Understanding the biology clarifies why timing matters:
The endometrium becomes receptive during a defined "implantation window" that occurs several days after ovulation (typically 6-10 days post-ovulation), not immediately after 5, 6.
Endometrial receptivity is established through molecular changes driven by progesterone, which you are already supplementing from day 15 5, 6.
The embryo itself (if conception occurred) releases signals that enhance endometrial receptivity, including hCG and other factors that improve the implantation environment 7.
Practical Recommendations for Your Situation
Given that you're on progesterone from day 15 and asking about intercourse one day after ovulation:
Focus intercourse timing on the days BEFORE ovulation (ideally 1-2 days before) rather than after, as this is when conception actually occurs 1, 2, 3.
Your progesterone supplementation from day 15 is appropriately timed to support the luteal phase and endometrial receptivity during the actual implantation window 5.
If you've already had intercourse during the fertile window (before ovulation), additional intercourse one day after ovulation won't improve your chances but also won't harm them 4.
Common Pitfalls to Avoid
Don't rely on basal body temperature to time intercourse, as it only confirms ovulation after it has already occurred and cannot predict it prospectively 1, 8.
Don't wait until after ovulation to have intercourse when trying to conceive, as this misses the entire fertile window 1, 2.
Don't assume that more frequent intercourse after ovulation compensates for missing the pre-ovulatory window—the biology simply doesn't support conception from post-ovulatory intercourse 3.