I had sex with my girlfriend on the 7th of this month she told me she was on the pill but I just found out otherwise, if she is pregnant then what are my options?

Your options are to be prepared if she declares you the father, and to order a DNA test after the baby is born. You could be stuck for 18 years of child support. You will have a tough time (impossible basically) proving she lied.

You have no options. You took that risk when you decided to have sex. No form of birth control is 100%.

So, you prepare yourself to be a father and support the child if she decides to keep it.