Looking for period related suggestions.

Before ovulation induction my period was regular & coming in 26-28 days. Then for first 2 months of ovulation induction I was taking Letrozole from day 3 to day 7 and then Duphaston from day 14 to day 28. My period had come on Feb 14 and then March 13 respectively. But on 3rd cycle of treatment, I took only Letrozole, but did not take Duphaston. I got spotting on day 19 and 21 but my period did not come. Then I took Deviry 10mg and got my period on April 25. After that I stopped taking treatment & did not take any medicine in this cycle. Suddenly I got mid cycle bleeding on May 8. It was period like bleeding for 2 days & then stopped. In TVS scan found follicle size as 18mm. My doubt is which date I will consider my last period date? Will it be April 25 or May 8? And next period date will be counted based on Apr 28 or May 8? I am out of main city, so unable to connect with my doctor. With lots of hope, I have logged in Practo for first time. Please help in confirming this. Thanks.