I haven't had a period for around 3 months. The last time I had sex I didn't use protection but I came on my period afew weeks later at my normal cycle time but it was for a day. It was very light and stopped after one day. After another day I came on again but very heavy and still only for one day. I took a pregnancy test and it was negative but I'm still worried because I haven't had another period since then. Im not excersizing too much and I'm not under or over weight so I don't see why they have stopped. Can anyone help please?

You will need to go to the doctor or health department and have a blood test done. If you did not use protection there is a high risk of pregnancy.

Are you using any form of birth control? Are you usually irregular?