Stomach pain

So the last few days I've felt really nauseous and I've had terrible stomach pains, it's constantly bringing me to tears. I've just changed to a new pill so I don't know if that's contributing, I'm really close to my period and I've always had bad periods but nothing like this before. It can also be very painful during sex. So if anyone has any ideas please help. Panadol isn't really helping either.