Your on the right track, the doe will stay in heat for about 2 or 3 days when she is ready to breed. I don't think the reason the bucks chase a doe is because she is holding out, she just isn't in heat. The younger bucks will chase does around because they are eager to breed and the does are not ready or in "heat". But in my honest opinion like wise to the post above, find the does/food and wait on the bucks to show up. I don't hunt a lot of buck sign, it is reassuring that he or they are in the area but I mostly hunt travel corridors, pinch points, saddles, and edges during the rut. The reason you want to hunt a lot during the rut phase is because the bucks are going to be most active during daylight and cruising ridges, saddles, doe feeding and bedding areas and travel corridors checking for a hot doe. Not sure what to tell you about the poop in the scrape except that they poop were they pee.