8week miscarry help!

My hubby and I were trying for our third for about 6months when found out we were preggo. We went to our 8week ultrasound only to be told there was no heartbeat. I am devastated. I can't imagine conceiving again only for this to happen again. So I would like to avoid my fertile window so I can grieve. With that being said when will I ovulate again?? I took cytotec on the 6th and I am still spotting. Will I ovulate before my next period? Help please?