Is this normal ?

I'm 15 weeks pregnant and I just noticed while wiping that there was some blood . I've had some sharp pains and a bit of cramping that last little bit but nothing I was to concerned about , also I've been having back aches a lot .

:S. this is my third pregnancy without any children so I don't want to freak out , I'm trying to be level headed . Ive never gotten to this stage in the game so I don't know what's normal !