Help! My female has been on her cycle going on 3 wks. Is that normal?

If you mean she's been 'interesting' for 3 weeks since she started bleeding, then yes that's normal - a season normally lasts approx 21 days, although it varies between bitches. If you mean she's been bleeding for 3 weeks, that's a bit more unusual.

M.

(Mental vision of SFT on a bike ....... :D)