Sorry but where you got this conclusion from? What drop you are talking about?
Referendum result caused BTC to spike up not drop and it is still rising since.
Yes, I don't see any relation between the two situations. I think it didn't affect BTC a lot and to say the true, there is already some time the votation for brexit ended... I think it's irrelevant for Bitcoins and crypto-currencies.
Bitcoin will continue increasing its price as normal, you shouldn't worry about it.