Last week. I've been leaving her alone and letting her recover and I peeked into her enclosure and it looked like she was showing her receptive colors again. Then I had pulled my male out of his enclosure and he saw her and tried to get to her. I wasn't having any of that so I put him back in enclosure quickly.
My ladies have kept their pretty colors and patterns ever since their first cycle. They have only very subtle changes when receptive or gravid. I go by if they are restlessly roaming all over their enclosures to determine receptiveness.