16 dpo? Please help!!!!!?

I'm at that really anxious time of ttc when my period is due and I'm experiencing a lot of symptoms which could either be af or pregnant. Some of the symptoms are: tiredness, sore bbs, intense lower back pain, headaches, nausea, and diarreah this morning (sorry a bit tmi) and frequent urination. I am also nearing 16 dpo and havent felt any cramping up until this afternoon (I always experience cramping the day before my af is due but hadnt had it up until now). I had a negative hpt yesterday but figured that perhaps my body wasnt producing enough hcg yet- or at least thats what I was hoping. This cramping that im having atm seems to be getting increasingly painful. Please help!