bleeding

I am probably along the lines of around 5 weeks pregnant.. two nights ago my husband and I had sex and yesterday I had some brown like discharge. Late last night I had very very mild cramping but red blood which scared me. I slept with a pad and had some more on it this morning than I would like to have. Not a ton at all and I don't think going at this rate I would ever soak thru a pad but I am going to ER. Positive thoughts and prayers would be much appreciated!!!