Early pregnancy or chemical pregnancy

Its been a week since I am waiting for my menses to come. Because I know for myself that usually I am irregular cycle. But last week I took PT and it came positive. I used to buy many different brand and it all came positive. But before i took PT. I got discharge like not that heavy its like going to be menses. I change my panty liner so thought my menses will come. Then later on the next day. It surprises me i dont see any blood comes out. Then i did was try to do exercise then it didnt happen. Thats the time I took PT and it came positive. The next day i took again positive. I went to see doctor, doctor said He cant find gestational sac he only see thick lining. He said its early pregnancy or pregnancy loss. I feel hopeless. :(