Well, generally, early periods do not indicate an early miscarraige. They can sometimes indicate an annovulatory cycle, or you could have ovulated a little early and be just having an abnormal period. A miscarraige is usually associated with cramping, or more painful than a regular period. I had an early m/c at 5 weeks and the cramps were much worse!
Also, as soon as I started ttc, my periods became wacky...probably from the stress of it and because I was thinking about it
Now my cycles range from 23-30 days, and as long as they stay within that range that is what I consider normal for me!
As far as trying again...they do recommend waiting a few months before trying again if you do have a m/c to let your body heal. If I were you I wouldn't worry about it