Hi My Friend Has A Pregnancy Problem And That Is

Hi my friend has a pregnancy problem and that is her hcg level not incresed in initially its positive but after 4weeks its negative she has a polysystic ovarian syndom she right now take a medicine to support pregnancy but I want yo know what is the reason that her hcg level not incresed she has a full hope this time but thing was wrong plz kindly help me to solve it