Brown spotting at 5week pregnancy.

Hi, Beta hcg 12300 on 18/11/2020,(15days post 5day blastocyst transfer) Tvs confirmed intrauterine pregnancy, with 2 gestational and yolk sack on  same day. My next appointment with my doctor is scheduled 2 weeks later.. Yesterday (21/11/2020) evening I saw few spotting( dark red) thought I was bleeding and contacted my doctor, was prescribed pause 500 thrice if bleeding continues otherwise not required, I took one tablet and there was no bleeding and I stopped the tablet, from last night I am seeing dark brown spotting( small tissue kind) whenever I go to loo.. No cramping so far.. I am taking duphaston twice, susten thrice all other medications as prescribed by my doctor . What might be the reason for this spotting, will it resolve on its own.. I am worried