I wish I'd seen this topic a bit earlier. I've just returned from my weekly yoga class, otherwise I'd ask my instructor about it.
I'd be careful to stretch the affected area even more since pressure and strechting is probably what hurt it in the first place. There can be some micro-tears in the junctures between hips/pelvic/tailbone etc. If that's the case, stretching will agravate it further and prevent healing.
A relative safe practice would be to find a calm and open meditationpose (sitting/lying) and use deep breathing to massage the area from within, opening it slightly with the inhale, and letting it come together with the exhale. Working the pelvic floor muscles in sync with your breath will help a great deal too. The fluid and membranes that run form your brain to your tailbone are very responsive to breathingexercises. Breathing also helps to "be with the pain" and that in itself can lessen the pain bigtime.
Another simple practice is to ask your hubbie to rub his hands warm and place them on your back where it hurts. The gentle pressure and warmth will help with the pain. Don't underestimate the power of the human touch.
O, and don't use painmeds and exercise at the same time, because the painmeds can cause you to unintentionally overexert the area.