Really bad PMS symptoms, or is this pregnancy symptoms?

Hi

I am 23 years old and have PCOS. I have ttc for about 4 months and have been on motorman for nearly 2 months. My last cycle was 36 days, but I have been on the pill for 2 years and my cycle has never been regular so I do not know if this month will be the same length. I do not no if I ovulated, but my period started on the 8th Jan and I had sex on the 19th, 20th, 25th Jan and 1st and 2nd Feb. Around 23/24rd Jan I started to get cramps in my abdomen. They were unlike any I have ever felt before, like someone was tugging my insides, they were throbbing and it felt as if I had a heat coming from them, after a few days it got really uncomfortable and I felt as if I was bruised inside. I was also very very windy, from both ends. I had soft poo, although that has stopped now. Now the cramps have calmed down, and are just in the background, hurting mostly at night.

On 2nd Feb I went to the doctors and had a pregnancy test done, which was negative, and the nurse said that I had a trace of blood in my urine. I went to the toilet later and had pink watery blood, with two red streaks in there. The next day, the blood had turned light brown and a very very light flow, I saw most of it when I peed and there was barely any on the sanitary towel. The past two days it has gotten slightly heavier, it is still brown but also slightly red, but still quite light, as my periods are much heavier, and when I wipe there is barely anything on the tissue but a bit more on the towel. I have also felt nauseous on and off, but last night was the worst and I was very close to being sick and I felt faint.

Today I am aching. My back, neck and my arms ache, even to type this message it hurts. I do not know what is wrong with me. I also feel like my head is radiating heat, if that makes any sense. I have never felt this before but I am starting to wonder if me wanting to be pregnant so badly is making me imagine up these symptoms. I was wondering if the light bleeding I am experiencing, is implantation as I would not be due for another week if the last cycle was anything to go by and I have never had a cycle this short before, usually I miss a month, but could this be the metformin reducing my period cycle, 

I am very confused. Has anyone experienced this before? Is my mind playing tricks or is this really bad PMS symptoms, or is this pregnancy symptoms. Your comments would be really appreciated.

Thanks so much!!