I think I have it sussed (If I haven't stuff it, we will all pretend I am right anyway ) You move to baby 2 at 4w4d baby 3 at 9w even baby 4 at 13w3d baby 5 at 17w6d baby 6 at 22w2d baby 7 at 26w5d baby 8 at 31w1d baby 9 at 35w4d Phew!
well done for that! Your maths is better than mine! I wouldn't even attempt it! I love moving on a baby, I'm itching to get to baby 7!