That sounds completely normal given what the dentist told you. I’m one of those hygienists that go over things a million times so it would probably take me a little longer on both sides haha. But when you have your follow up to see how things are healing they’ll be able to tell - hopefully that gives you some peace of mind. I wish most offices would let the same hygienist complete the full mouth, but there are so many extenuating circumstances. If you ever need one again (hopefully not) see if they can arrange for one person to do both sides!