Leia openly admitted her belief that they got off too easily from Death Star - they only sent 4 fighters after them instead of hundreds. So she knew she was being tracked (the 1976 novelization 100% confirms that with more details).
If so, why in the world did she make Han fly Millenium Falcon straight to Rebel main base on Yavin, leading Death Star straight to it? (they didn't know where the base was before that!) - instead of, say, having Han fly her and Luke to some waypoint and changing ships on the way, or at the very least, scanning Millenium Falcon for tracking devices thoroughly for a week while hanging out in the middle of uninhabited space?
NOTE: Leia clearly did NOT give up Yavin to Imperials during interrogation, otherwise Vader and Tarkin wouldn't need the tracking device so much:
" I'm taking an awful risk, Vader. This had better work."
So, there doesn't seem to be any rush to reach Yavin ASAP.