Molar pregnancy🥺

I had a molar pregnancy back in September and had emergency d&c September 27th. I have been following up with my hcg levels and last Friday they were at 6. I decided to take a test todaay to see if was all gone cause 5 is considered not pregant. But i took test today and the line is still showing postive. Has this ever happen to anyone? I have had sex with my husband but use protection but im wondering if the tumor is growing back? Or if i got pregnant again?

How long does it take for hcg level to drop one?

Can a urine test pick a level hcg at 6?

Im sorrry im so at lost🥺