I'm 20 years old and I'm late by about 17 days. Ive done 2x home tests that both showed up negative 1x urine at the doctors and 1x blood test at the doctors... both showed up negative. I don't know what's wrong with me... I think that I am because my nipples are enlarged, I've been overly tired, I'm bloated and look like I've gained weight only on my tummy, my boyfriend says I'm moody, I get hot and cold flushes and I've been eating a lot more. Please help I don't know what's going on with my body and I just want answers... I have always been regular with my period since the age of 9!

Yes they can my mam had numerous pregnancy tests when she was having my sister and only from having a blood test at 5 months pregnant did it say posative. Se your doc and ask for a blood test