opps 🙊

Soooo I've just had a beautiful baby 4 weeks ago, and I couldn't help but have sexual intercourse with my SO as it's been a loooonnggg time, his been so patient and understanding so I thought I better give this poor guy a break, we got into and he kinda had an accident inside of me and I'm worried about what I can do to avoid getting pregnant again, as the midwife told me it's possible and I'm not breastfeeding much anymore.. 
Anybody have an suggestions, my partner wants another one straight away and I know his going to persist but until I'm 6 week after baby my doctor can't put me on any birth control. 
Could I get the morning after, even though I'm still breastfeeding slightly?
TIA 👍🏽