Hey, I Think I'm Pregnant, Experiencing What Could Possibly Be

Hey, i think I'm pregnant, experiencing what could possibly be history's worse case of morning sickness. The chances are slim though because I have IUD & because a month ago i had (unrelated) knee surgery &prior to going in gave me a pregnancy test which I assume was negative since I didn't hear anything further.
Ive researched a little & read it's possible to get false negative w/ hospital tests after a certain point in pregnancy.
My question is whether or not the otc tests maybe more accurate in the aspect they'll get a better reading?