Hi Dave and Welcome to TFF!
I don't think that short stint at 7ppm will have had enough time to do anything negative. We don't like to get up to 8ppm because it will start to encourage the wrong species of autotrophic bacteria but it takes really being up there and for a pretty long time usually to have a negative reaction like that. Yours will be fine.
Do you feel pretty confident about the type ammonia you found and the test kit you are using? One other detail that helps is to understand that you should have a regular "add-hour" withing the 24 hours, when you test and then add ammonia if it has gone to zero ppm within the previous 24 hours. Even if you test ammonia at zero ppm with a 12 hour test you still wait until your 24 hour add-mark to add more ammonia. Also, once you get the nitrite spike going strong, you can ease down to adding only about 3ppm (rather than 4-5ppm) for the duration of the spike, but then ease it back up to 5ppm after the nitrite begins clearing in 24 hours.
As you probably know, fishless cycles average anywhere from 3 weeks to 2 months or more and its extremely random how long any given one takes or really what its exact progression looks like.
~~waterdrop~~
