First I missed my period for 2 mths, 71 days, then I got my period earlier, 25 days cycle, is there something wrong in my system, never happend before?

Probably not. It sounds like you just didn't ovulate normally. This happens to everyone occasionally. If it is recurrent, you may have polycystic ovarian syndrome or some other hormonal imbalance that is affecting ovulation. Your cycles should return to normal in about a month, especially if this has not happened to you before.