I have had my period and had two negative home pregnancy tests but something just doesn't feel right. I've also noticed my stomach is beginning to get bloated and have been having quite a sore back and head and strange kind of feeling in my stomach I'm also feeling very emotional from high to low to angry etc for no reason as well as needing the toilet a lot more frequently than usual, I just feel something isn't right, what could this be?

Illness, stress, hormone changes, etc. there could be many possibilities. See what happens when you expect your next period. Test again at that time if it doesn't show. If you continue to feel poorly, see your doctor for a check-up.