I know exactly what you're feeling, I get anxious about things too and look crazy stuff up which makes me worry more! I seriously doubt its ectopic though, online it says ectopic pregnancies only effect 1.9% of the "pregnant population", so, its pretty rare! The risk factors are: maternal age, current smoking, previous ectopic pregnancy, previous tubal litagation, previous ongoing genital infections, & previous IUD used for b/c.
So, unless you have more than 1 or 2 of those, its extremely unlikely. Don't stress girl (easier said then done, I know)!! :)