does anyone know how Plan B could effect a baby?

I took Plan B the morning after I had sex because I was on antibiotics so I wanted to be safe... turns out 6 weeks later I found out I was pregnant. I'm keeping the baby but I'm really worried that the plan B could have caused harm to him or her :( I told my doctor I took it but my first appointment isn't for another week to discuss everything. 
Any advice? I've researched it a little bit but I feel like it's making my anxiety worse about it. 
Edit: I'm 10 weeks this week according to the free clinic I went to for a date scan and to make sure the pregnancy was viable. Baby had a heart beat (162 ❤️)