My girl friend and I had sex on the last day of her period and I think just a little got in her. She takes her birth control as far as I know. She also has irregular periods sometimes. From experience how likely would it be that she gets pregnant

If she has been taking her birth control on schedule, odds are low. Even with birth control pregnancy sometimes happens, however. All she can do is just wait and see what happens when she might expect the next period.

Is it more likely to get pregnant right after a period is ending ?

It would depend on when she happens to ovulate. Not everyone follows the norm and a person can have an occasional off ovulation... which is what can cause a period to be off from the norm.

Thanks you have been helpful

If this was recent, in the last couple of days, she could get emergency contraception, such as plan b, as an extra precaution.

You are aware of how statistics work? There if you had sex... even WITH protection its possible. COndoms are 83% effective WHEN USED CORRECTLY. THat means 17% of the people that use only them correctly will end up pregnant at some point.

Some women can and do get pregnant even ON their period.

You could have gotten her pregnant the second you inserted yourself without protection... you don't evgen have to finish.

So now the waiting game starts... you both wait until she is at least 2 weeks late for her next period. There is nothing you can do until then.

I know TWO women here that got pregnant while using THREE forms of birth control correctly... one had it happen more than once.

No form of birth control is 100% effective.

Thanks. I was using a condom but once I ejaculated did not pull out (idiotic mistake) and was just concerned that some possibly got out

ANY time there is penile insertion there is the risk of pregnancy. You can minimize the risks but not eliminate them. To minimize the risk you need to understand the process.