Its normal.. I found out i was pregnant at 5 weeks and couldnt hear the babys heartbeat until 8 weeks
Excuse me, 5 weeks and 6 days counting from the first day of your last period, however long yours lasted. It doesn't sound far off though. Good luck and relax.
Is the 6 weeks 2 days your own calculation? If the last day of your period was Feb 6, then you figure you ovulate around 10 days after, which would make you approximately 4 weeks and 6 days pregnant from the day of ovulation. Sounds like their measurements are right.
Probably too early to see anything.