Trying to conceive - help!?

This might seem like an odd question but my husband and I have been trying for our first baby since september. I know this is not a long time in real terms but it's hard as each month goes by. We have been using vaseline as a lubricant (tmi sorry!) but am wondering whether this might be affecting our chances & I couldn't find any clear info on the web. Does anyone know if this is likely?