Kinda worried. 6 weeks pregnant.

So last night my husbad and i fooled around for a little bit. Not a big deal. This morning i had a decent amount of dark brown discarge and i have been wiping up a light light brow discharge all day so far... thats not what concerns me... whats concering me is the cramping that have been coming and going for the last hour... it comes and it feels like i have to poop combined with lower cramping you would feel during a period last about 5 minutes and leave for about 10 minutes... any ideas?