Suggest Treatment To Avoid Miscarriage

Hi Doctor, I have had 1 chemical pregnancy in a fresh IVF cycle, 2 miscarriages in FET cycles (both around 5 - 6 weeks) and one spontaneous pregnancy which I miscarried before pregnancy was cpnfirmed. Now I am in my third FET cycle. My beta HCG level on 10 day past 5 day embro transfer was 219. On the day of test I had small cramps and started bleeding silghtly. First it was brown mucus now after 3 days it has changed to fresh blood spotting with mucus. Am I miscarrying again ? I am on progynova,crinone gel and ecosprin .. Now the doctor has prescribed duphastone additionally.. Also does taking bed rest prevents early miscarriages ? My APLA test is negative ...