Do you think I had enough yeast?

I made an ale with an OG of 1.053. I was making a starter and I opened this White Labs vial without shaking it. Some of the yeast came out from under the lid and I unded up wiping the vial off and throwing the escaped yeast out.

So I made my starter like normal and pitched at about 70 degrees at about 10pm on Sunday.

My beer started fermenting right away the next morning and had build up a nice head and was bubbling away nicely on Monday. On Tuesday the head had completely disappeared but was still bubbling but much slower.

Without having to open up my carboy and take a gravity reading do you think I should pitch some more yeast?

No don't pitch anymore yeast...you're not the only one to have ever had an "explosive" time opening up yeast tube...You made a starter and it took off...so let the little guys do the work...they'll finish up eventually.