Wife had a miscarry. 1st period after that came 15days late and 2nd in just 15days. We are worried. ?

Not to worry. Unless she is having significant blood loss (more than a normal period) i would give it 3-4 months for her hormones to stabilize and return to a normal non-pregnant levels and resume normal periods again. If periods continue to come twice a month after 3 months (as long as blood loss is not severe) then you should seek evaluation by your local gynecologist.