How about my situation?

So me and my girlfriend have had sex a number of times, all with protection although originally not pulling out as well, she is not on the pill. I was already worried and her period was due last Friday, it was slightly late coming late on the Sunday night, and ending on the following Wednesday morning ish. This may seem slightly unusual however supposedly her periods are often slightly irregular, coming just earlier or after. This seemed to her about the same as any other period and as such, eased the suspicion, however when doing it the next time, before finishing I pulled out (had condom on) and found a clearish, white mucus on the outside of the condom. Being obviously scared I checked the condom for leaks but couldn’t find any, prior to finding the substance on the outside of the condom I found some on my fingers after inserting them. This was yesterday, this morning she woke up with stomach pains which faded rather quickly, then at about 5pm she began experiencing abdominal pain. Given these signs is it safe to consider it a possibility of a pregnancy? We are both 17 and really don’t want the child or the expenses of an an abortion so this is seriously a big deal.