Help? Maybe a dumb question

Hi! About two weeks ago I had my first time. I trust the person who I had it, and we used protection, and he came outside, but I'm still worried. Can't ask my mom bc she is really...weird with that subject? I had my period, I'm on my forth day today, but it was a little bit lighter than usual (no spotting). I'll visit the doc in about two weeks, and I know it is almost impossible, but I'm really worried! Do I have a chance of being pregnant? Please help.

Also, sorry about my English. It is not my mother language