Pregnancy Scare W/Mirena??

I’ve had my Mirena IUD in since June 2018, my period was gone until I finished breastfeeding in November 2018 and it’s been back and regular (literally always in time) until last month. My last period was August 24th, my boyfriend and I have constant unprotected sex and I’ve been having weird symptoms. I took a test Monday and it was negative. I’ve had some spotting after some rough sex but other than that no period in sight 😭 any advice?? Anyone dealt with this before? My gut is telling me I’m pregnant, I have an appointment with my ob/gyn Tuesday 🤧