Lost my baby

I had a miscarriage 18 days ago I should of been 10 weeks from my last period date but baby was small one dr said 8 weeks 3 days but scan at er said 6 weeks 4 days so really have no clue how far I was they think I lost the baby from a chromosomes problem my husband and I have been trying again since I stopped bleeding but how do I know if I'm pregnant again or not I never took a pregnant test after losing my baby to see if it ever went back to neg and haven't had a period yet since losing the baby