My Stella is about 1/2 way through her third week in heat, and this is my first experience as well. I got the doggie diapers... used 4 of them, and none of them stayed on very long, but they helped while they were on.
Definitely keep an eye on her at all times. Stella became moodier, and more determined to get into things. The past 3 weeks have been really stressful, on top of the noticeable discharge, she has seemed to develop selective hearing. She also decided that she doesn't need to tell me when she needs to go out anymore, the door should just magically open for her when she gets there, and if it doesn't, well then she'll just pee on the floor right in front of it!
Thankfully as she is progressing through and her hormones are calming down, she is beginning to return to her old loving self! Light at the end of the tunnel!!!