Should I be worried? please read..

So since having sex yesterday I've been feeling a bit off.. I had cramps last night that felt a bit different to the ones I usually have but thought it would pass so let it go. Now I've been having cramps consistently for about 4 hours and have a weird burning feeling in my side. My belly is also hot to touch. Is this normal or should I go to the ER? I'm 16 weeks btw