I have had a similar discharge and my OB checked and did swabs to ensure it wasn't amniotic fluid or an infection, I was lucky and was given the all clear, I am on drugs to calm my BH's as they were getting out of control as such and being high risk, we needed to calm everything down.

But as it is coupled with a constant period pain, I will call your MW or OB or care provider to just get checked out just incase, if it is an infection they can treat it, but it would have to be diagnosed properly as different infections require different treatments.

Infection can also cause PTL, so not worth the risk, and best to get it checked out to be safe. Big warm and I hope that it is just normal discharge like I am experiencing - it literally drips out (sorry for the TMI) and is coupled with popping feelings as well. But it is good the know that for me it is "normal"

Take care and thinking of you xxoo