Sorry BiB, coming into this late. ******* went into heat a 7 months, she really swelled though. Thought I'd tell you that just so your ready!! hehe. Hope she get's better soon.
Day 1 of a heat cycle is the first day you see blood. With my bitches, there's usually been a 7-14 day lag between when they started to swell and when they actually started having any discharge and really went into season. But every bitch is different.
It seems like they do the most swelling at the first season, too..the poor things wind up looking like some of those monkey butts you see at the zoo. And every doberman bitch I've ever owned became a total hormonal mess during their first season-they just didn't have a sensible thought in their brains.