i had to ring the clinic on day one of my AF then i had a scan after about 7 days this being on a natural cycle after that had scans every 3-4 days till follicle they were watching was ready to pop to indicate i had ovulated then after that was 4 days before had ET
but i would check with clinic as they all do it different
I am currently waiting for FET (due on 6th June), like cooter I had to phone the clinic when AF started, I was then booked in for my time planner (or whatever its called ). I am doing a medicated FET, so I started injecting for DR on day 21 of my cycle. I had baseline scan on 19th May approx 2 after starting DR, I then started progynova day after baseline, I am due for another scan on 2nd June to check linning thickness. If all goes according to plan ET will be 6th June. So it has take a month all in all (though it feels longer!) but it works out to be 5 weeks. I have counted from the date that I started injections.