Hi I'm 18 and feel that I might be Pregnant.

I've been eatting a lot more food then usual latly, been constipated, dull backpain, sometimes I feel kind of sick. My stomach just feels different and kind of bloated. And I just don't no what to think. I no I should take a test but I think I'm just going to wait and see if I get my period which should come in a week or so...
Also I got my period last month but it was kind of different then usual...
Thanks for your help :)

Oh and I forgot to say, my nipples are starting to feel tender which never happens and my boyfriend told me they look bigger and a lot rounder