Brown discharge and spotting between periods does not necessarily mean you are pregnant although it could very well be the case. A number of other things which could bring about the same result is:
1. Late exit of old blood from the last period. (This will look brown)
2. It could actually be your period! This happened to me and it freaked me out as i did not expect my period for another week and it was never brown like this before. This brown discharge lasted approximately 5 to 6 days. I still went to the doctors to get a pregnancy test which came back negative. She told me not to expect my period as what i experienced WAS my period.
3. Brown discharge and irregular periods can also be brought upon by stress, change in diet, or interrupted sleeping patterns.
4. Injury or tearing due to sex.
5. It could also be a number of more serious cases eg polyps, cervical cancer etc
If you experience any pain, or excessive bleeding, or the discharge smells really bad please have this checked out. Or if you have any concerns you should have this checked out anyway.
I hope this helps. I had researched an enormous amount and had many sleepless nights waiting to find out what this could all mean while waiting for my blood test results. I just felt that most people on many different forums jumped to quickly to the conclusion that it was a pregnancy and i felt i should also point out that it could be so many different other things as i mentioned above.
Main rule: if in doubt go and talk to your doctor.
LT.