I can you ovulate twice in a cycle?

Erin

So I missed my period and was hoping I was pregnant, but all tests were negative. Just out of curiosity I took an ovulation test and apparently I was ovulating again. I was scheduled to ovulate August 26 and the tests showed peak fertility, but no EWCM. Sunday I did the ovulation test and showed peak fertility, and yesterday I had EWCM. Is it possible to ovulate twice or have a second fertile window if you don't release an egg on the first?