L - did you have a trigger injection to make you ovulate? If not it can sometimes take longer for af to arrive. I waited 8 weeks 2 days after our cycle was abandoned. I had a scan on 8 weeks when my lining was exactly the same thickness as when we abandoned and I had one large follie. I was going to be prescribed provera to bring on af at that stage but the description of its side effects (the nurse did the psycho music and mimicked stabbing) on moods scared my body into submission. Since then I've found more posts on here from people who had a long wait for af. Mostly when not given a trigger.
It's worth calling your clinic as they may call you in for a scan sooner than mine did and that could help to put your mind at ease. The only other thing is, is there any chance you could have conceived since the abandonment? I was told to keep testing (though boy was that hard to do).
I really hope your cycle sorts itself soon as I know how hard it can be.
Cathie x