Blood work after BFP

I took a test on Tuesday morning FMU and it was positive, had blood work done to confirm it on Wednesday - number came back at 18. Ha blood work done again on Friday at the exact same time as Wednesday - number came back at 60! I'm still so worried about it sticking. We've been trying for a year and 9 months. I'm also on Progesterone 400 mg every night for the first 10 weeks. My first ultrasound is scheduled for June 5th. Do you think things sounds promising?