I'm having some concerns. I've been spotting occasionally, but it does…

I'm having some concerns. I've been spotting occasionally, but it doesn't last long. I've been urinating a lot at night and during the day, and my period is missing by 19 days now. My stomach looks really big, and I don't know what could be wrong. My last period was on January 15th, and it hasn't shown up since then. I had unprotected sex every day after my last period, and my boyfriend ejaculated inside me every time we had sex. I haven't had sex in one week, but I had sex again yesterday.