Call your OB/GYN and tell him/her what you are feeling... and about your body!
That is the ONLY way, to tell.
I have NEVER heard of 'flu symptoms' being the indicator for labor.
It sounds like you are sick.
Rest, stay off your feet, drink lots of water because it helps contractions etc.
But TELL your Doctor... about your increase in Braxton Hicks/cramping, and pain/tingling in your vagina....
OH! And if you THINK you lost your MUCOUS Plug... TELL YOUR DOCTOR!
I lost my mucous plug.. and the SAME day, I was in labor.....
CALL your Doctor and give him/her the head's up!
38 weeks is safe to have a baby. Both my pregnancies was early. My first pregnancy was 1 week early. My second pregnancy was 2 weeks early (I had a c-section)... and both times, my kids were born FULLY formed, over 8 pounds each and 21" long.
good luck,
Susan