Need Advice

I am 17 weeks pregnant and I have an infected toenail..I called my OB 5 times and never received any calls back, I saw my primary care doctor about a week ago, she said it looked fine but gave me Cephalexin if it didn’t resolve. Well I got home tonight, and my toe was hurting and there was a small amount of drainage..I went and picked up my prescription..is Cephalexin 500mg okay to take? I would call my OB but the fact they can’t return any my calls is so frustrating and I don’t want to hurt my baby..thank you in advance