Plan B pill 5 weeks postpartum ???

I had unprotected sex with my husband and I am 5 weeks postpartum. Is it ok to take the PLAN B pill? Has anyone done it before? 
No, I don't want to get pregnant again. Yes, I should have thought about it before having sex. 😫
No, I am not breastfeeding.
Yes, I called my doctor's office and I'm still waiting for the office to call me back.
Please help!! 🙏🏻Thank you!!