A man doesn't have to be a super man to make his wife pregnant at one shot. It is normal, and it happens to many. Believe me! So, your PILs expectation is not really wrong. You guys must have met minimum 20 times in this 6 months of marriage, and this is fairly a very good frequency to become pregnant unless you have other plans. In this case, be upfront and explicitly tell the family members that you are yet to plan your family. This minimizes a lot of issues down the line. There you are... You really need to establish a good foundation in your marriage before you expand your family. Enjoy this initial stage and use it as a medium to get to know each other. Travel together and spend some quality time before you are on pregnancy mode. Once you become a mother, you will always be a mother only... I mean, your children will steal all your times!