Being pregnant your nose swells sometimes making it harder to breath out of it, while making allergies horrible and nose bleeds to be a result of your nasal cavity swelling. Its completely normal.
That's happened to me a lot and with pregnancy, especially around how far along you are you can gain a lot of mucus. I've had a lot of mucus my whole pregnancy and I'm 31+1. I wouldn't worry about it
I'm 20 weeks and just last week i had this happen..then the next day I woke up with a horrific cold still can't shake it! Hope you don't get whatever I did its been miserable!