Did you have feeling it was twins?

I am 4 weeks and 2 days pregnant and have strong feeling there could be more than 1 in there. This is my 4th pregnancy and I got a very clear BFP at 10 dpo and with my others I never got a BFP until day of period or after. I have nausea already and EXTREMELY exhausted. I am wondering did you twin mommies know before your first ultrasound there might be more than 1? I have to wait till 12/18 for my first appt and ultrasound. How far along were you when you found out it was twins?