Am I pregnant?

Okay so I had a period January 29-February 4 and my SO and I had sex a lot since we got back together at the end of January like I don't think there was a day we didn't have sex.  We had sex while I was ovulating and we didn't use a condom he just pulled out but there was 1 time when he misjudged and came in me. I had a really light period a week and a half later that lasted February 13-17. I'm currently 23 days late. Today I started feeling nauseas and I took 2 pregnancy test last week and they both said negative. I have endometriosis and PSOS so I'm afraid it may have been wrong. Any advice?