I'm 16 and had unprotected sex on the 26th of January and he ejaculated in me. My period was already 3 weeks late so I don't know if I was ovulating. Could I be pregnant? And if so when would I start getting symptoms and when should I take a test?

If you had sex, then the first sign would be a missed period, did you have sex prior to this last missed period ? From the sex on the 26th of Jan, it will be about 4 weeks before you could test, up to 6 weeks, if after 4 weeks, no period, do a test, if that is negative, do another test in two weeks.

Why ware you late three weeks already ? Where you having sex in December ?

No I didn't have sex in December - my periods are just very irregular!