Foal heat is usually 7-10 post foaling, right?
trying to figure what is normal for Sophia, she only has two registered foals, she may have had more, but her breeder doesn't always register colts (fillies are all registered).
She had a filly 6-3-2011 and a filly 5-10-2012, that's 342 days apart. So, if she came into heat 7 days after foaling, that would be 335 days gestation, if it was 10 days after foaling, it would be 332 days ( a little shorter to account for length of cycle).
If all this math is right, and she happened to take on that April 24th breeding day, 332 days would be March 22 (a bit better than when I did the math wrong). If she took at the later date (first turn out on pasture was June 24), that would be like 2 months later.
I won't panic as much about a possible 10-month foal with our crappy weather. Not that we can't be crappy the end of March, but it's 30 days closer to spring, so every day helps.