Hi,
After the transfer of frozen embryo, the 
implantation in the lining of 
uterus may start after 1-5 days. Though normally, increased 
hCG levels for 
pregnancy may be detectable after 9-14 days. Therefore, to be conclusive, a waiting period of 14 days is advised for home pregnancy test.
However, if the implantation might have been early on 1-2 day, then a positive test on 6 or 8 day is a conclusive positive test for pregnancy. You may also note other symptoms of pregnancy, like spotting, cramps, 
fatigue , breast tenderness etc. To be more confirmed, a quantitative test for HCG levels may be undertaken.
Take care. Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Satnarain Bansal, General & Family Physician