I had a period on 12th of december. on the 30th, i had mucus with a bit of blood in it, but he pulls out every time before he comes. could i be pregnant or is it period?

Possibly: Pregnancy is a posibility. Purchase and perform a home pregnancy test. It should turn positive by the time you're a week late. If it's negative, repeat it in 1 week.

Probably neither: The mucous and staining you describe in the approximate mid-cycle of your period may be a normal response to the slight drop in estrogen that occurs at or near ovulation. The rising estrogen right before ovulation leads to increasing mucous; the drop in estrogen at ovlation may occasionally lead to staining. Just for the record, pulling out before ejaculation may not protect against pregnancy.

Neither: Most likely the mucus and spotting you had on dec 30 was due to ovulation. If you're periods are regular, i would expect a normal period mid- january ... Unless you are pregnant. The "pull-out" method is not a reliable way to prevent pregnancy.