Today I went for a long walk to pick up my daughter from nursery and it was fine, few BHs but nothing much at all. Tonight when putting her to bed (bout 7pm) I had a few period pains and went to the toilet and they sort of went away but I've been left with a really sore stomach. It feels a little bit like I've done 1000000 sit ups, really sore and deep. Also have a sore groin and a headache What is this? have I overdone it?