I'm 17 weeks today and on friday evening my SO and I took our daughter to an arcade and my SO and her got on one of those motorcycle racing things and I was standing beside them so if she fell and my SO lost balance and the bike slammed all of it and their weight into the side of my tummy. I've been sore and had off and on cramps but havent thought much of it but me and my sO had sex this morning and was fine but I just went to the bathroom and was spotting a little and have been a little crampy this afternoon. Is it just probably irritation from the sex or something more?