Spotting and mild cramps

At 4 weeks I had slight pink discharge once when I wiped. Dr ordered me beta HCG and progesterone which came back fine. Today 5 weeks 4 days I have woken up to quite a bit of light brown discharge when wiping and a few dots (tiny) of red blood. I began to have mild period type pain. This lasted for around two hours. My doctor said I am likely to miscarry. I had a scan a few hours ago and everything is as it should be for 5 weeks 4 days. Sac measures correctly and fetal pole and yolk sac present. Too early for heartbeat. I am going out of my mind especially as I had a chemical at 4 weeks and missed miscarriage at 9 weeks last year. I have to sit tight and hope for the best. Please have me in your thoughts. Xx