Yeah, there are lots of tiny blood vessels near the surface so the force and repetitive coughing/sneezing can just end up bursting them, Carnation. You've had it before so it's likely just more of the same.
The time to worry with blood is when it's an abnormal amount. If you were coughing up spoonfuls of the stuff then something needs investigating. But specks are nothing.
I hope you feel better soon. I have always hated hayfever season. I'm pretty lucky these days as it doesn't affect me much now but years ago I used to wish June away every year!