Pregnancy and dental work = Scared?

I broke off a quarter of one of my molars right down to the nerve and below the gums 2 days ago. I had alot of swelling and pain so I went to the walk in clinic yesterday night to see the on call doc ( I was unable to get an app with my doc ) she recommended that I see a dentist right away and that just because I am pregnant doest mean I cant have something done for my tooth. Anyways this morning I managed to get an app with a dentist. After taking a single xray it was discovered that the tooth was abscessed, non repairable and also had another tooth trying to grow in underneath it. I ended up having the tooth pulled. The dentist was well aware that I am 8 weeks pregnant. He used local anaesthetic and nitrous oxide to yank the sucker. He told me that both were ok during pregnancy and that the baby would be fine. I am panicking now because I googled nitrous oxide in early pregnancy and nothing that I read has been good. Im so scared and regretting having the tooth pulled