New to Glo and feeling unsure...

My husband and I have been TTC for 5 months. I am 30 and I went off the pill (Minesse) in January and my first 4 cycles were ideal. Had a 25 day cycle and my period would last 5 days. Last month and now this month my cycle has been a little odd in that I have had spotting for about 4 days (starting when my cycle day 1 should start) and then a period for about 3-4 days thereafter! Any ideas on why my cycle could all of a sudden be irregular? My gynae has said not to worry about it and it will all sort itself out but that is always much easier said than done! Any help or advice???