I Am 8th Week Pregnant Through IVF. I Had Brown

I am 8th week pregnant through IVF. I had brown spotting on last Thursday when I was 7 week 4 days and it turned to red on Friday morning. I called my hospital and suggested to Trapic E twice a day and asked to come if it continues. On Saturday morning the spotting color changed to brown again and I went to hospital. Doctor did US and told it looks good and suggested for hydroprogestron inj and duphaston twice a day. Sunday I was ok and today morning again I coud see red spotting even after taking medcines... Could you please advice why I got spotting again even after medication.