I was meant to start my period on the 20th of April, but still no period. Its strange for me not to have a period 2 months in a row. I have taken a pregnancy test but it comes up negative. My boobs are really achy and have really dark bug veins running through them which they didn't before. Can i be pregnant but the test doesn't show?

Im 20 years old. Healthy, normal weight for my height.