Stumped.

Me and my husband have been TTC for a year and a half now. No luck at all..here the past few months I've been nauseated and my breast are really sore and I've went up 2 bra sizes in the past 4 months with horrible stretch marks on them. I've stayed about the same weight though and have had regular periods. I've looked it up and where I looked they said it is possible to have a regular period and be pregnant. What do y'all think? Any stories or helpful tips? Please comment?