I assume that your last period so far was on 20th of June. Assume that you are having regular cycles, the consumption (fusing of egg and sperm) might have happened sometime 1 or 2nd week of July. Which mean by now the fetus is approximately 12 weeks old.
This is means your long term boyfriend is indeed the father.
Moreover you has a periods after the May incident. So this rules out the May incident as the possible cause of your pregnancy.
Hope this helps
Please feel free to ask followup questions.
Patient replied :
So is there no possible chance that this pregnancy could be the result from the may incident?
No. Especially since you had periods after that incident pregnancy is not likely from the May incident. Thank you