opinions advice?

I'm 22 years old and I have one child she is three I have been trying to convince recently but have miscarried twice my periods are right around 5 days long and the cycle length is between 25-22 it ranges and when I get them it's so heavy that when I stand up it's running down my leg and My cramps are really bad well i recently went and got my blood drawn to confirm pregnancy because I had all the signs and a at home test came up positive it's was a faint line the blood test came back negative my last actual period was April 6-10 and on April 28 I started to bleed but it was so light of a bleed than would stop and than lightly bleed agin until may 2 now I'm normally 95 pounds and have been my whole life my diet has not changed and neither has my life but my nipples are darker and my stomach is sticking out so bad that my family is asking me if I am pregnant but the blood test came up negative I took a cheap at home test last night and it said negative I'm so confused as to what is going on I haven't really been thinking much of it cause I don't want to get my hopes up and something go wrong