I did take 2 home pregnancy test but both came out negative

I am 26 years old I use to have irregluar periods until I got on birth control when I was 22 and I am 5"1. My bf and I thought long and hard about starting a family so last September on the 20th I stop taking my birth control. My periods were still every month. In October it was lil early november it was 2 days late with bad cramps same with December but period was right on time. In January it was right on time but no cramps nothing at all. My bf and I had sex when my period end the same day i ended then I started to have some uncomfert like mil cramps here and there stomach feel different when I lay on my side. I also started to notice blue vanes on my boobs shoulders and across my chest. In February and March I have not had a period. But still continue with mil pain nauseous on and off tired moody and headaches more o fften then before. Hungery at odd hours that use to never eat at. I did take 2 home pregnancy test but both came out negative. I am planing to take a another one this month on friday. But of it comes out negative again I dont know what else to do. I dont have much money to go to the doctors but I think that what I might have to do next. My boobs do hurt sometimes too and my pants that fit me 3 months go dont fit me anymore and i seem to beging weight fast within 3 months but like i said we dont have alot of money so i dont bearly eat enough to gain weight that fast. But please any advises would 've great please help me