31 weeks & 3 days

Sorry in advance for the picture but this is the first time this happened when I was 28 weeks and then again today it was twice as much this morning but I didn’t take a picture. I am 31 weeks and 3 days pregnant with my 4th child. Last time I was told it’s discharge and it happens especially in the 3rd trimester. I’ve been crampy a lot as if I was on my period and my lower belly hurts also hips and lower back. Is it just normal discharge or my mucus plug??