Advice on early labour signs

Loredana

I found out baby was engaged 3 days ago, at 36 weeks, on Saturday I will be 37 weeks. Last week I passed something that I thought it could be either normal discharge or mucus plug, please see pic below

Anyways, since that, I've been getting more and more lightning crotch and very painful ones, that I cant even walk, if I walk more than 10 min, I start getting very bad cramps. And now since this morning I've been with diahrrea, and some cramps.but not many, plus a bit of nausea, I can feel baby pushing down when I'm sitting, which makes my vagina starts cramps while he is doing that, but very irregular, I've been feeling very off for 2 weeks to, plus my nipples are incredibly sensitive. This is my second pregnancy.