Chemical after miscarriage at 9 weeks

Kate • Sun, Feb 14

I had a miscarriage at 9 weeks in December ‘20 with multiple complications including retained products and infection. Had a D+C late December and got my period in January. Then we started trying immediately after this and I got a positive pregnancy test 2

Days ago and now negative. Is this a common thing to happen after miscarriage or should I go and get myself checkout out? We have been trying since October.