When Should One Retest For Pregnancy After Using Letrozole And Experiencing Symptoms Of Hormonal Changes?

Hi I am TTC for 1 year now. Doctor gave letrozole in the first week of cycle then Fertigyn 5000 injection on day 16, 2 eggs raptured as per report. I am taking Duphaston and Folic acid tablets as per our doc adv. I tool pregnancy test on Day 27th of cycle negative result I got.I am having cramps and severe breast heaviness along with bloating. Please advice when to take next test and whether is it some hormone changes I am experiencing.