I've been running 3-5k on most mornings for the past year now. Into my 6th week of pregnancy now and can't stop running (though only 2k now).
Not sure if it's 100% safe to run throughout the pregnancy. I've had no morning sickness so far (so was I with the 2 previous pregnancies -- only I did not run at all then), so it is quite easy to get out of bed in the morning...
Desperately need all those runners' advice out there!!! Thank you!!!