Positive pregnancy tests

On 26th September, I met up with a girl I didn't really know and we had sex without a condom. She told me she has been having an injection ( contraceptive for 9 months ). I didn't ejaculate inside her. Today she told me she thinks she is pregant, she has had sore nipples, feeling sick and off her food. She said she has done 3 pregnancy tests, 2 with Clearview and one with Boots own brand. One Clearview was positive and the other negative, the other test was also positive. I am hoping that the positive tests were somehow wrong. She claims she was pregnant once before and miscarried also has some health problems such as chronic fatigue syndrome.

The chance of her being pregnant when she is having an injection AND I didn't ejaculate in her must be very low, so therefore I would have thought she isn't pregnant, but the 2 positive results seem very strong evidence that she is pregnant.

I just don't know enough about it all to know if it is likely she is pregnant or if the tests are showing positive for some other reason. Can anyone with more knowledge/experience give their opinions.

Thanks