Period or implantation bleeding?

I haven't had a cycle in three months. I'm pretty irregular. Feb 14th I had sex and on the 18th I had creamy cm with a light pink tint. It lasted for a few hours and then stopped. The next day no bleeding but when I had a bowel movement I would get ewcm tinged with blood then nothing. That went on and off for two days then I had very light bleeding like my period but no cramping and no clots just light bleeding that lasted for two days. On the 24th I got real nauseous from the food I ate and threw up thought it could be food poisoning but bf ate same food and he was fine. The nausea has been on and off since then. I haven't had major symptoms just extremely tired and emotional not sure if I'm pregnant or just over thinking. Called nurse, nurse said there's no way I can be pregnant with what i described but friend of mine keeps saying it could be a baby. Please any insights or personal experiences with this and got a bfp