Af gone haywire

Hi ladies.. So for 2 n half years we have been ttc.. My cycle has all of a sudden gone funny.. It's always been 29 days dead on.. 2 months ago it was 26day this month it was 23days.. This month I ovulated on day 8 of my cycle.. Dont understand as I've not changed anything and always been so regular.. Waiting for Ivf consultation appojntment.. Hopefully will come through soon! X