I really don't understand why so many people on here are so desperate to see twin 'signs' when they haven't even had an ultrasound yet, "I'm nauseous, could it be twins?" "I tripped could it be twins?" "my pregnancy test line was really dark, could it be twins?" RELAX, I get wanting to have twins but nobody can tell without a clear sonogram. There's no definitive signs to having twins without a sonogram.