First I would like to thank everyone on this forum, it is very helpful and informative. You all have a great site. Now on to my situation

my gf recently started the patch. She started her period on dec 9 and started the patch the same day. The first week went by and everything was normal. Now its the second week and she has started spotting. This will be the 3rd day of the spotting. We have not had sex in the last 2 weeks. Her period is usually every 28 days. This past period was on the 31st day and the period before that was on the 26th day. We have had unprotected sex before, although I was only in her for a couple of seconds and I did not ejaculate. I do understand that pre-cum can cause pregnancy but the last time this happend was over a month ago. My question is, do you think the spotting is a cause of the ortho evra patch? (she was on some bc pill over a year ago and it didnt cause spotting) or do you think she could possibly be pregnant ? (she has never missed a period) thanks for the help, I really appreciate it!!