Help please?!?!

So I had my period 2 weeks ago, since then and even before my boyfriend and I have been having unprotected sex, he'd pull out (he questioned his pull out game one time) I just got put back on my birth control a month ago and the last few days I've been very nauseous with the feeling of throwing up, I have had severe headaches, and I've been bloated. I find myself having trouble sleeping due to the constant ache of my back and the occuring cramps and sharp pains. I have bled lightly and experienced brown and pink discharge, today is what really set me off, I fell asleep with boyfriend and I woke up crying about cake lol and the last 2 days when we have sex I bleed a little after words. I'm just wondering anyone's personal opinions on this and whay could be happening.