So, you don’t have a last period date to go on, or you’re cycles are irregular enough to not know which end is up. How do you know how pregnant you are? Is ultrasound the last resort, the only way? For so many women it is, and many doctors insist on routine ultrasound when there isn’t a period date to go on. But for those opposed to ultrasound (or for those just wanting that first pregnancy challenge) there is another way.