Discharge in pregnancy

16 weeks pregnant and having a small amount of very thick, clear but nearly white, mucusy discharge. It is like the consistency of boogers. I had a larger amount of it come out last night, but it was clear, almost yellow looking. Now since then and all day, every time I use the bathroom I have a small amount of it, but it's not the same color. I am having some cramping pains so I'm getting worried. I haven't had any sort of discharge at all this entire pregnancy.