M.C.
Hi Bonnie - I'm 37 and my husband has been snipped. Last year I missed a period too, and took 2 pregnancy tests, both of which came back negative. However, I was worried because there is a (very slight) chance of getting pregnant after a man's vasectomy. I talked to my primary care doctor/GYN about it and she said it is normal to miss a period every now and then, especially as you get older. So if I miss another period this year, I won't be worried. And if your pregnancy tests were negative, I think that's a good sign that you're not pregnant.
Take care and all the best,
M. C.