Slow rising hcg

Halee

So I got my hcg levels checked on Monday since I have a history of ectopics. On Monday at 4:30 they were 49. They had me come in Wednesday at 9:15 and they were only 64. Then today (Thursday) they were redrawn at 1130 and they were 80. Doc doesn’t seemed concerned because they’re rising and will have me repeat on Tuesday. I know I’m SUPER early but arent they supposed to at least double?! Are my chances of MC pretty high now?