HCG levels tripled in 2 days

Sorry for being annoying with all my posts I'm just a worrier, so bear with me please. So I found out Monday that I'm pregnant (literally Sunday morning was negative and Sunday night at like 12:15 am technically Monday) and had blood done that same day and the hcg levels were 15 than I had blood done again Wednesday and today found out my hcg levels tripled to 50. But I had to hound the office for the results and the midwife never called me to discuss the results, should I worry? I think the numbers tripling is good and to me her not calling means nothing to worry about if it were cause for alarm she would have called but IDK maybe I'm a worry wort ugh hate this thank you ladies!

Edit: according to my period I should be almost 6 weeks but bc I ovulated a week later I think I'm almost 5 weeks

Edit Edit: my Midwife called me back and said that my numbers are doubling appropriately and to watch out for etopic pregnancy because my numbers are a little on the low side but I could just be really early and two expect to not to see anything when I go for my ultrasound in 2 weeks because I'm so early