Confused

[Donk_]

So I was out for a party and I was drinking already and had to use the restroom and then I spotted baby pink so I stopped right away but I already had lots to drink . I assumed it was my period coming by it was the only time I spotted pink Then the next day I started spotting brown . I was suppose to start my period may 25 but I didn't and then 4 days later I went to the restroom and had a blood clot that was black . And then the next day after that I had 2 more and that was it . Now its been 4 weeks that I've been spotting brown . Yes I took pregnancy tests and all 3 came out negative. And today and yesterday I notice I felt nauseous . And just a little sore ness on my lower back and front .