Pregnancy after depo? Only had 1st shot

Kyra • Happily married to my best friend, mother of an amazing little boy. I am a dental assistant and I love what I do!
Hey all! I had my first shot in August... And I have bled every other week since! I just stopped bleeding yesterday... I was due to get my shot this past week and didn't go for s couple reasons... First it was a terrible experience and hubby and I decided we're ready for baby #2. Since I've only had one shot does anyone know if I could get pregnant right away? It's also confusing because of all the bleeding.. I'm unsure of what's my period or what's just out of whack.