Hi I Had Miscarriage But When I First Started Bleeding

Hi I had miscarriage but when I first started bleeding I went to er they did my blood work hcg level was 37 they gave me rhogam.i followed my doc after a week she did lab I was 82 and told me to come for another lab I went it came to 34 then I was ok but on January 8 I had my periods do I needed another shot?