It’s been 41 days since the beginning of my last period. Should I be worried?

Haven’t had sex in 4 months. Have spotted every month similar to period. Negative pregnancy test. I don’t know what’s going on. Had sex in October. Took a test in November and it said negative. In December I was sick and nauseous “period” came late. Didn’t take test because I got spotting and assumed I wasn’t pregnant. January again got spotting like period. Now it’s February and it’s been 41 days since the beginning of my last period. I took multiple test strip pregnancy test from amazon that weren’t expired of the same brand and all 4 were negative. I’m wondering if I’m too far pregnant that the test isn’t giving me a REAL answer. Stomach at the bottom part is big. Even when I don’t eat much calories it seems to still be growing. Everyone notices and says I’m gaining weight. I feel insecure. October I went to a sperm bank and got artificially inseminated. So I don’t know what to believe. I’ve been throwing up and not eating much because when I do eat it goes to the bottom part of my stomach. I feel sick and my head is killing me. I’ve been taking ibuprofen. If I’m pregnant I’m like 4 months pregnant.