What Causes Brown Vaginal Discharge With Stomach Cramps And Headaches?

Hi. I am 28 dpo. 9 dpo I experienced when I went to toilet dark brown discharge when I wiped (only happened that once). Then nothing for 2 days. Then 11 dpo I went to the toilet again and had pink discharge when wiped (only happened once). I have had no bleedin/discharge since until today 28 dpo which was only once, orange coloured discharge. I had done several home pregnancy tests all negative and blood tests all negative. I have cramps in pelvis/hips, excruiating back pain radiating from hips right up, constant headaches, nauseous, reflux and heartburn, sore nipples and breasts feel like about to explode, fluttering/movements in belly, belly is quite tender and cant sleep on it, pain to the left of my belly button. I think thats everything but I cant afford to pay for you. And no one is willing to help me find out whats wrong with me