I had unprotected sex for 10 seconds & then stopped. he didn't ejaculate. i'm 2 days late with usual period signs but do you think i'm pregnant?

Possible: Unprotected sex in the absence of ejaculation can lead to pregnancy as minimal amounts of sperm may be expelled even before orgasm. Two days is a short amount of time. Home pregnancy tests are very useful when needed.

Possible: The duration of unprotected intercourse isn't important. You could still be pregnant or have acquired an STD. To know for sure if you are pregnant, do a pregnancy test and, if it is negative, repeat it in 3-5 days. Hope this helps. From now on, be safe and use protection every time until you are ready for a baby.