how to tell my average cycle length after miscarriage??

before my miscarriage April 2nd, 2014 I got my period every end of the month any day of or after the 25th for 3-5 days. now since the miscarriage I get my period around the same time but not the exact dates. example: April started on the 12-14. May started 11-15 & June 14-17. Sooo how do I know my average cycle length now? what would you say it is and why? ? please help!