Yin yoga, stretching, running

These past couple weeks I've attempted to become very serious about evening yoga -- in the style of yin yoga, where you hold poses supported only by gravity for 3-5 minutes, and I do mostly hip openers. Pigeon, butterfly, supported extended butterfly, piriformis stretches. It's a nice way to wind down and Penny joins me, she loves the yoga strap and we make up poses. Forever and ever my chiropractor has told me, you need hip openers and looser hip flexors! So this was an attempt to work on that.

But I've been wondering, when in the hell will I start to see any improvement in baseline flexibility? I can stretch as long as I like but the burn of the stretch doesn't seem to lessen...well now after a week of way more intense activity (so more muscle and fascia movement in general) where I've gone for two run/walks and had my regular Thursday spin class as well, I sat down after my run today and bing! Better baseline flexibility! Huh. Does it take other people this long to notice a difference? Acro pals? Anyone else with regular stretch practice past or present?

I find it interesting that although I think "yes yoga every day I want to be that person" I also think "oh god yoga every day is that really what it takes?"