I think I might be pregnant?

I think I might be pregnant but I don't know about some of the symptoms because they're different from my last pregnancy. Well first off we have had every other day unprotected and now I think I'm 8 dpo. I don't have any sore or anything but a little cramping here and there and once in a while a weird sensation or twinge of nausea especially when I get up from sitting down or laying. I am extremely tired often. Was supposed to have AF due in 6 days but I don't think she'll show, I feel like something is different but can't put my finger on what. I have been EXTREMELY emotional too but then all happy all of the sudden. It would be pregnancy number two after one baby and a miscarriage. Your thoughts? Do the symptoms fill out?