Primolut to induce period

Hi ladies! I’m on cycle 56 and I haven’t had my period. I had an UTZ done 2 weeks ago and sonographer said endometrium is thick which is just about ready to shed. But it’s been two weeks and still no period… I am wanting to start primolut to induce period. I have taken it before for about 3 cycles. Off the top of my head, my OB then told me 3x/day for 3 days then period comes in 3 days which it did. I just want to confirm this with anyone who has had the same experience. Is it three days?? I know most of the time it’s daily tablet for 10 days.. But not sure which route to take. Any advice/suggestion/insight would be very mch appreciated. Thanks again! We are TTC, btw. 😊