hi dunno,
sorry to hear about your loss
my miscarriage required a D&C so my situation is slightly different, but the similar none the less. i only spotted a few days after, but it took 91 days for my Af to arrive
(i am normally very regular). during that 91 days i litterally climbed the walls thinking something was wrong (or i was really UTD and all the tests were wrong ) i had major nausea, tiedness, constapation, a UTI, tonsilitis, and about 3 colds
what i am saying is that being preggers (even for a short time ) takes a lot out of a person, and how we recover depends on lots of different factors.
my advice listen to your body, if you need reassurance get a referral to a FS, have them look into your spotting and your cycles, so that by the time you are ready to TTC, you will be in tip top condition.
BTW nothing you did would have prevented the miscarriage.