I had an affair with a woman who I met over the internet we met twice and she fell pregnant. I do not want anything to do with the baby as I feel she was trying to trap me, she told me she was on the pill so no condoms were used and apparently antibiotics she was taking caused the contraception not to work.
I am married with children and would like to know do I have to pay maintenance for this child?

I would recommend a DNA paternity test, but yes you can be obligated to child support if the child is proven to be yours or if you sign a birth certificate.

And yes antibiotics can caus things like that to happen. Have you told your wife yet that you may be a potential father?

I'm sorry, but if you are expecting sympathy you came to the wrong place. You cheated on your wife and family. And you got caught at it. And now you want to duck the responsibility for your actions. Fortunately (unfortunately for you), the law doesn't work that way. You were a willing participant in the act of sex. You were an irresponsible participant in relying one someone other then yourself for protection. You cannot duck your responsibility for this child, if you are indeed the father.

This women will probably file for child support from you. You will be entitled to have a paternity test done to prove whether you are the father or not. If you are, then you will be required to help support that child.