Hi, there are lots of different methods of contraception (preventing pregnancy) so your wife should go and see a doctor to find out what's best for her. In the meantime you could usr condoms, available at supermarkets, pharmacies and family planning clinics in most western countries. What is available to you depends on where you live. If you have no other method available to you then look up the rhythm method on the internet. It is not totally reliable but its better than nothing. Also, you can try removing your penis from her vagina before you ejaculate. Again this is not reliable, but better than nothing. I would not recommend these methods to unmarried couples or teenagers, but in your situation, if there is absolutely no other method available then they are a partial solution. But it would be much better if you can see a doctor about this or usr condoms. I hope that helps.