Peak fertility after a week?

Sarah-Louise • I live in Oxfordshire with my husband Rich, son Bertie and Molly the cat.
Hi everyone,
It's been a week after my AF ended and this morning I took an ovulation test (out of curiosity) which came up with peak fertility.. 
My cycle is normally 36 days.. Shouldn't peak come 2-3 weeks after? Surely this isn't right.. I'm thinking maybe my body is all over the place after my MC
Anyone have any advice?