I am so sorry for what you are going through. I am right there with you, I know your feelings all too well (check out my post above yours from yesterday! BAD day). It's so hard

Personally af did not take long to come for me with each of my 2 chemical pregnancies. The 1st time I started spotting & that was what tipped me off that there was a problem with my pg. Af came on full force within a week. The 2nd time af also came in about a week, maybe a week & 1/2 ,after finding out that my betas weren't doubling properly & another m/c was inevitable. So I never had to wait too long to m/c (thank God). My breasts were still tender too even while I had begun m/c bleeding, I guess b/c the hormones are still there.
One interesting thing is that af came both times before my betas were at zero. My RE said there was a chance that my 1st m/c was ectopic, maybe that's why? (Betas don't fall as fast with ectopic pgs; they don't continue to climb but they don't dive either, the # stays more stable-ish).
Well, if your beta is 8 then I would imagine that it should be down to zero within 2 or 3 days (if it goes like mine did). Make sure that you stop supplemental Progesterone if you are taking if, that will hold off af. Also, my Dr still has me on Met, are you still taking yours, I think you should be?
BTW, my RE is doing a while slew of b/w after my next (natural) af to see if there is another reason why I have m/c'd twice. The test for chromosomal genetic problems isn't covered here until 3 m/c's but there must be some simple & inexpensive blood tests your Dr can do to see if there's an obvious problem that is fixable? There's absolutely no reason you should have to risk going through a 3rd m/c if they can find some obvious & correctable reason!!!!!
In case you want to ask your Dr, here is the list of what my Dr is checking (I am copying it off the requistion):
-Coagulation: -INR, PTT
-Factor inhibitors: -Antithrombin, Protein C, Activated protein C resist., Lupus anticoagulant, Protein S (PRS)
-Hormones: -Prolactin, TSH,
-Immunology: -ANA, Anti-DNA (double), Rheumatoid factor, Anti-Cardiolipin
Good luck, don't give up hope. I know it's so so hard but we have been pg twice, & that's more than some people. At least we know the egg & sperm can meet
If you want to talk you can pm me (doesn't seem to work most times) or email me:
lisenior@hotmail.com.