Infertility. Suggest i do in this case?

Hello, I'm 36 years old and live abroad. My period starts with spotting (dark and brownish blood) and I don't feel any period pain until the heavy bleeding. The heavy flow always starts on 6-7th day and bleeding ends by 9th day. But my fertility doctor asked me to count heavy bleeding day as day 1 of the cycle. My first IVF failed. Don't know the reason why. They are now preparing to thicken my endometrium lining by giving me estradiol and progesterone hormonal medicines. As I will be going through 2nd IVF cycle, the doctor and I are afraid if the ET happens between 18-20 day of my cycle (counting day 1 when heavy bleeding starts), then the spotting will start in 1-2 days during the time of ET. I also do have small fibroids of 25 mm on the front and back of my uterus. My doctor said an infection in the endometrium could cause this spotting. We will do biopsy next week to find out the cause. What do you suggest I do in this case? Please suggest. I'm so worried and stressed. Thanks