Good question. In the mortgage industry, there is a 45 day cycle. Intially you have a 14 day window for credit inquiries. Following that 14 day window, you have a 30 day waiting cycle (also known as a deduping period). On the 45th day - 14 day window + 30 day waiting - ALL your initial credit inquiries only count as ONE inquiry. So you can have your credit pulled hundreds of times and it only counts as ONE.
So what if you have your credit pulled after the 14th day - say the 15th, 16th or 17th, then the 45 day cycle starts all over again. Also please keep in mind that credit inquiries only account for 10% of your total score anyway.
Try to make sure that you're not also opening credit cards, or buying a new car on credit at the same time, as those would be counted seperately.
It's the same way in the auto industry - just a shorter period. You have the same 14-day initial window for credit inquiries, then there is a 14 day waiting period (30 for mortgages) and on the 29 day, "all" the credit inquiries that occurred during the intial 14-day window only count as "1" inquiry.