Hi, me and my boyfriend have been trying to have a baby, my last real period was on June 16 and it was 6 days long. I have my period every month around that time. But in July I had a misses period and on August 5 I had a 2 day period, it was super light when I usually get heavy periods and well it was brownish at first and I barley even had blood and when it was over, I had mily stuff? I've been having cramps after that and I've been having little sharp pains that started on my left side below my ribb cage and now its on the right side and below and above my belly button, the feeling is becoming less and less every day but the feeling comes and goes. It's the 18th and I'm still having them, I also get really constipated, and I get bloated easily, I also get a lot of mild headaces its usually one side and then it goes to the other. I've never had this experiece before, I've take 3 pregnancy test but they all came back negative. I don't know what to do, I'm really sad because I want to have a baby, does anybody know what could be going on with me, somebody please help me.. :/

Since you have been trying to get pregnant, and your periods are off the norm, it would be time to see your doctor and ask about a blood test.
Some women do not get a positive right away on urine tests. If you are not pregnant, they can try to determine another possible cause.