Thanks for you query.
I read your query and I understand your concerns.
Following is my reply:
1) Having sex 2 days before expected period is unlikely to be leading to pregnancy
2) If you are anxious about pregnancy, please get serum beta hCG
test done. If negative, relax and wait for cycles.
I hope I answered your query. I will be available for any follow up query you have.
Dr. Mahesh Koregol
IVF & Infertility