Rude people

I have been trying for two years to get pregnant. This has been such a stressful time for me because this road has not been easy. I came here for answers hoping someone out there has had a similar experience. I know if you have a period you are not pregnant but my best friend keep telling me her grandmother has had her period with all three pregnancy. My best friend has a child and so does everybody I know. I can even remember my child hood friend telling me her sister in law had hers. So in my mind I believe them and I think maybe that's because I really want to be. I came here hoping someone could help me better understand it since most of y'all have been trying for a while. I did not come here for y'all to be freaking rude towards me. I know I need to take a test. That's not what I asked y'all! I know y'all not in my BODY! I thought I explained it the best way I could be obviously I did not! I'm just confused because I thought sperm last for five days. I had unprotected sex on the 17 and the 19 I ovulated. If I ovulated two days later which means the egg drop the sperm should have gotten inside. That's what I thought so I just don't understand why my period is down. No need to put me down for not understanding for asking a question to something I do not know.