Pickled head woman woes.?

i've met an old friend a few weeks ago. we slept together and ive been textin her back and forward since. i used to fancy her when i was younger and still do. a little. she is hinting for me to ask her out, but i am scared to get into another relatioship so soon after splitting from my ex who i still have very strong feelings for. i want to get back with her, but dont want to wait forever. we split about 3 weeks ago. should i go for it and take it easy or wait and see if my ex will come back. i long to settle.