This email clinches it:

“[The]…conspiracy theory about Dick Cheney getting his wife pregnant to avoid the draft suffers from a fatal flaw. Women are not pregnant for 36 weeks (9 months), but rather 38 weeks. What’s more, the range could go up to 40 weeks…meaning that if the baby was born 9 months and 2 days after the rule change, the baby was conceived before the change [in the Selective Service draft policy].”