Is the possible?

3 or 4 weeks ago I had a miscarriage at 4 weeks. While I was miscarrying I took a test and the test line was faint. So after a week of bleeding. I guess you can say we tried again but we wasn’t really trying and last week I kept getting on and off spotting and some symptoms that I had when I was first pregnant. I haven’t had my first period yet after the miscarriage. So yesterday I decided to take a test just because and it came out positive and I know it’s not left over from my miscarriage. I can’t believe I got pregnant that fast after my miscarriage weeks ago. Is this even possible?