Yes this happened to me as well and I worried that it didn't work because I was told it normally takes 90 seconds. I think that mine lasted around 30 seconds. My doctor also checked with the scope and said it looked like a good burn, My doctor aslo checked with the maker  of the novasure because this short time my doctor never experienced and they said that 90 % of the burn happens within the first 15 to 25 seconds.  I still have periods but they are so much better than before. I am also going thru peri menapause which kind of mixes it up alittle, but I am so much better of than before the ablation. It took me a good six to eight months to see my actual results so I hope you have patience. Good luck and hope all goes well for you.