Trouble staying hard

This week was the peak time to TTC. We BD mon, tue, & wed no problem and enjoyed it! Thursday before work we tried and he wouldn't stay hard even with more specific attention there. Friday we again tried in the morning and he couldn't keep it going. (9 years together and this has only happened like three times) We have good quickies in the morning regularly so it's not that I'm rushing him kind of thing. 
He blamed it on his cold so I was understanding. Then he said he was going to rest up and feel better. Saturday, he spent the whole day with his cousin working on the snowmobile. That's not resting and getting better in so pissed! Married for three years and TTC since July. Still waiting for my Christmas miracle.