So...does the depo shot really work?

Myah

I got the Depo Shot on November 28th, and it has definitely kicked in by now. The thing is, my app said I am late. I had unprotected sex (without a condom yesterday) and he claimed he didn't "pull out" fast enough and he came inside of me a little.

I am just worried because this is the first time this has happened.

Let me know!