ectopic pregnancy symptoms ?

so the last time i had my period was the 21st of February. after not getting my period i got scared and took a pregnancy test on friday night. that was negative. i took another on saturday morning with the first urine of the day, came out negative again. after thinking that i just might not be pregnant i tried to have sex with my husband but within the first min. i had extreme pain in my pelvis. how to explain would be saying like my ovaries being blown up like a balloon and ready to pop. i was stuck on the bathroom floor in pain for about 20 mins.

i have no idea what the hell is going on with me lately. i had stopped the nuvaring a few days before getting my period. i only used it for about 3 or 4 days because it was annoying the hell out of me. i don't know if that makes any difference.

my mom said it might be an ectopic pregnancy. i looked it up online and i have some of the systems it notes. (ex. lower back pain, pelvis pain that comes and goes and varies in pain, my breast seem more tender but doesn't hurt, and for extreme cases it says neck and shoulder pain, and that's what i have now.) does anyone know what else it may be?
i'm trying to get a doctor (since i just started living here in italy i have to go to some place to fill things out still) but if the pain doesn't go away by friday night i'm going to the hospital. oh and how long does the baby have to grow until it becomes too big and burst? if anyone knows. thanks very much for reading.