Discharge and pains

I'm just over 17 weeks pregnant, over the passed week I've been having so much discharge, at first just white, turned to white and clumpy (like cottage cheese) and now it's got a little yellow tint to it, earlier as I was sat on the toilet, I felt something slip out, very similar to what a blood clot dropping would feel like, I looked in the toilet but couldn't see anything. I'm also cramping more recently (more than I have with my first pregnancy) and now if I stand up from sitting or kneeling I get a sharp pain shoot up quite deep in my stomach. I'm calling my GP tomorrow, but just wanted to know yall's opinions too. As I read on Google, thrush is quite common in the second trimester, and cramping can be worse after a c section because of the scars? What do you all think?