Spotting/bleeding

So... a few weeks ago my husband and I fooled around and after i had a bit of bleeding and was gone by the next morning. Last night i woke up at 3 am and everytime i wipe there is pink and not much of it, but this time i didnt do anything (like sex) to bring it on, I just have a really bad cold right now.. where im sneezing and coughing constantly. Has anyone else had this? No cramping or anything. Im between 9/10 weeks my dates have been all over the place, ive had an ultrasound at 6 weeks and they say the heart beat... but this is seriously discouraging me.