please help!

Araceli 🎀
So yesterday afternoon i went to my local clinic to confirm pregnancy as i got a positive Saturday evening with frer test. My period isnt even due until the 8 of January so the urine came back negative so she ordered blood work so i got the blood work done and she said she would call me today with results, well last night around 12 am i had really bad acid reflux and went to the et there they confirmed my pregnancy with urine and blood work l, blood work was at 74 and today the doctor from my local clinic called and said my hcg was at 81 yesterday evening before i went to the er now im worried as it seems it went down a few numbers. Can it just be doffrent sensativity? Someone help keep in mind my period is not even due yet