How long does it take for the Depo shot to become effective?

Hi ya’ll,

I just received my first depo shot yesterday and I have been hearing/reading different wait times of effectiveness. My gyno initially told me it takes 3 to 7 days. Then I read on Planned Parenthood that if you get it within the first 7 days of your period (which I did, I got it on the 4th day of my period) that it is effective immediately. Then when I went to go get the shot at my gyno’s office yesterday, the woman giving it to me told me a month. I’m just super confused because I’m going to go see my boyfriend on Friday so I’d like to know if I am safe to get came in or not. (Lol sorry tmi)

Someone please let me know haha

Thanks!