hcg level 22???

So I had a m/c exactly 5 weeks ago ( I was abt 6 weeks preggo) and I bled for 3 days and after 1 week my hcg levels were down 14 and I also took pregnancy tests 2 and 3 weeks after the m/c and they both were bfn. I've been experiencing pregnancy symptoms lately so I took a pregnancy test yesterday and I saw a faint line ( see the pic)..went to the doctor ..they also got a faint line..so they made me do some blood work. Today my doctor calls me and says that my hcg level is 22 and she believes I am 5 weeks pregnant. Isn't that too low for 5 weeks? can hcg level increase after a miscarriage even if there's no new pregnancy? I am going in for another blood test on F

riday.. I am just freaking out! If I am pregnant, am i going to have another miscarriage cause my level is so low?? has anyone had levels this low? I think I am more like 3 weeks!