Obviously I can’t give a % because there is far too many considerations. For example, what if he came like an hour before, or what if she was ovulating and in the peak of her fertility window? Like I could be very low like <3% but it could also be as high as >30%. Now I’m not saying that these were the circumstances, but the nature of this post indicates that these aren’t the type of people to think about these considerations beforehand.
Please know I’m not trying to be rude, but that’s not how probability works and you aren’t considering any of the nuance here. There are multiple studies reporting that it’s actually quite common for conception rates to reach around 20-30% for a single encounter in a single cycle during peak fertility windows. But here's the thing, these numbers refer to the middle of the bell curve, the typical cases. Of course, there are people whose chances of conception well exceed 30%.
I’m glad you’re trying to look for accurate sources, but you’re still not understanding that averages do not convey the absolute max or ceiling of likelihood. While arguing a single paper isn’t productive, I want to point out that your source finding could also use some work. The same authors from your source updated their work and stated that they were incorrect and they state an average probability of 9.7% babe.
This was one of the lower reports I had seen and the study had a pretty small sample size. Regardless, I never was interested in arguing specific percentages, I even said in a previous comment that there’s no way to give a single percentage due to the level of variance. My only point was that your comment saying “incredibly low” when you have almost no information (and probably no background) to support that claim is highly misleading and I was curious what you were basing that on.
A single statistic about the average time for a couple trying to conceive has basically no discriminative power in the context of this person’s likelihood of getting pregnant. Also even in the most charitable assessment where we assume the numbers you give are correct, it still is misleading to say the chances of getting pregnant after any unprotected sex encounter are “incredibly low”. Like how do you not see that.
Let’s consider what we know about OP: It was their first time and they came to yikyak for advice about pregnancy. Do you think they are tracking their ovulation correctly or at all? Given that it’s their first time, how likely do you think it is that their partner is experienced enough to get ideal execution of the pullout method. They are probably young, which would increase likelihood of better sperm motility, higher maximum survivability duration, and maybe even higher sperm count.
Regardless, I don’t think we are making any progress here and I want to reiterate that I’m not trying to be rude, I just was hoping to introduce even a bit of the nuance that you left out of your initial answer. Have a good day and sorry if it came off like I was being overly blunt