Ttc for 2 years

Hi there I'm debs and I've just joined ... Basically my story is this !!! I have been taking clomid for nearly a year now I have 1 more shot left with clomid !!! i had my first IUI 2 1/2 weeks ago !!! My breasts are aching feeling dizzy and was sick earlier !!! Bloated and tired a lot more than usual !!! Not sure if this is AF or implantation bleed started today .... Colour is red then light brown when I go to toilet .. Tampon doesn't have much on it ... Myself and my lovely hubby to be !!! are so desperate for us to be pregnant !!! It took until the past few months to get dosage right on clomid as kept over stimulating .... Had to be 1 or 2 follies only so I now take 1/2 tablet on day 4 and same again day 6 .... I also have low back pain too ... Please folks could u give me some advice could I be pregnant and still have a bleed it isn't a lot and colour of it has been changing throughout the day 

debs xox