Pregnant or stressed?

I havent had sex in about 4 months. My periods havent been normal since june, and this month im about two weeks late already. What should i do? Ive already taken multiple hpt since june (last time i had sex with my SO) but they said negative. Ive been bloating lately, having some pelvic pain since the other day, my eating has gotten worse though (food just makes me want to blow chunks), and ive been feeling extremely tired lately. I dont know if i could be pregnant, or if its just stress from my SO being away in the navy and me starting school this senester. What do yall think?