You can get a $1 test at the dollar store they work jus as well as the $20 test or Have her go to the health dept they can give her a test but more then likely its jus stress something when u worry about ur period u will make it late or it could be the time of year or jus anyhting that made it a lyl late but if yall have had actual sex in the last month there is a chance of her being pregnant birth control doesnt work 100% that how I had my 1st kid I was on the pill
Periods can come late for a number of reasons, stress/anxiety and medication being two of them, even on the pill. You don't give much information, so I'll have to make assumptions.
If her period was due 1 November, the chances are she could have ovulated on 18th October. You 'messed around' (a bit more detail would help) about two weeks (?ago?), so was that on 23rd October? A released egg is only viable for about a day or so, so your activity was at least 3 days after the egg was viable.
However, if her ovulation was late so that she ovulated on or after your activity, there is a potential risk. But you do not say on what date you had the activity.
She is on the pill, and has hopefully taken them properly, and has not been ill. Even so, the pill is not infallible. What pill is she on? How old are you?
Your pre-cum could have contained sperm, particularly if you hadn't urinated since your last ejaculation. Sperm can live in your body for several hours. Also, research has indicated that some men's pre-cum always contains sperm. But for conception to take place, sperm has to find it's way into her vagina. So how close was the head of your penis to her vagina (the entrance to the canal), and how wet was her vulva?
It may be that her period comes tomorrow. The symptoms might indicate her period is imminent.
Hope this is a help.