Implementation Bleeding. To concive.

Hi, I am having pcos so I consulted fertility doctor she suggested me siphene 100mg I took medicine for two months Feb and March. In the month of march i took tablet from D2 to D6, 12th day undergone scanning for egg devekopment, doctor told me egg developed very well and pelvic movement is also very good you can go for natural try same way we have done. On April 14th i had 2 to 3 drops bleeding, i read in internet this may be implementation bleeding, early sign of pregency. Later I waited for period due date is 17th April. I have missed period as well but unfortunately today 19th april I got my period. My concern is why I had 2 to 3 drops of bleeding on 14th april. Is that not implementation bleeding. Or after implementation is there any reason failure of pregency. Or this is early miscarriage. Please let me know the reason. Advice any other medicines to concive.