Welcome to Just Answer and thanks for your question. When was your last menstrual period? How long between periods (usually 24-30 days)? Also, are your cycles generally regular (generally the same number of days from one period to the next)?
Thanks for the additional information. You can only make an educated guess. Ovulation is the most likely time to get pregnant and that is about mid-cycle. For someone with a 28-day cycle, that would be Day 14. Let's assume you have a 28 day cycle. If you started your period on April 25, then the next period would be expected May 23, and ovulation would occur about mid-cycle or about May 9. The egg that is released at ovulation lives for just 24 hours. Sperm can live for up to a week after ejaculation. Intercourse from a week before ovulation (May 2) through the day afterward (May 10) would have the best chance of fertilizing the egg.
If your cycles are exactly 28 days like clockwork, the odds would favor the guy on May 9 being the sperm donor. However, women don't work like clockwork, and it is possible to ovulate several days early or late. We always recommend that if you've had intercourse with more than one many during a cycle that you have a paternity test when the baby is born to learn which one is the father.
There is no way to tell from the pregnancy test which one was the father. Regardless of which one it was, the test would have been positive. Tests only tell that you are pregnant, not how many weeks pregnant.
In April my menstrual period was real late and from my last period March it took 34 days before my period came on in April, so does that change the story in any way and the partner on May 9 didn't ejaculate is it still possible that he is the father? And I also want to fully understand my question but i am definitely going to accept your response.
The longer cycle would more heavily favor the May 9 episode, but you should still have a paternity test, since ovulation is not on a perfect schedule. It is seldom exactly on schedule even if cycles are exactly 28 days apart just like clockwork, and you note that your April cycle was late, so you aren't regular.