It depends on what you use. If all lubrication prevented pregnancy, there would be no need for the Pill.
Using lubrication won't make it so you don't get pregnant, but it can make it harder for some. Lubrication can immobilize sperm and make it more difficult to conceive.
They say the best kind to use is " Pre-Seed". It actually helps while getting pregnant. It's sperm friendly. :) Over here in the states you can get it at CVS but I'm sure you can find it online. Good luck hun!! :)