Period changing

I've never had problems with my period, never had cramping or anything. Lately, I've had cramping, tender breast, all the works. This last period was only two days long and I had two huge clots pass the first day! I'm still super tender and moody but my period was done two days ago. There's no way I'm pregnant with a period like that, right? I googled for help about what could have changed and that's what led me to the pregnancy thoughts. Thank you for your help!