Sorry to butt in but always keepin an eye on you all
I had mild OHSS but it started about 3 days before i was due for preg test not after EPU. The DR was 100% convinced this meant a BFP as you only get OHSS at that stage if there are baby hormones. My symptoms were:
really sore and distented tummy (looked about 5 monthes pregnant)
Could only sleep on my back raised up on 2 pillows
It hurt when i walked
and horrid nausea
The FS said stay at home and bed rest heaps of fluid and powerade etc, low carbs and if i start vomiting go straight to emergency!
Hope this helps