Hello! i had unprotected sex in January and started my period a week and a half later at the normal time... and then february i missed my period... i have also started dieting and working out... should i be worried that i could be pregnant? also sometimes i go months without a period
If you had a normal period when you expected it, then it is unlikely you are pregnant.
You can always take a home test. By now it should easily be accurate.
Changes in your diet and exercise can also cause you to be irregular.
I doubt you are pregnant.
Hope it helps.