Hello, I would just like to agree and say, YES, you can definitely be pregnant and have every indication that you are about to start your period.
I took an early pregnancy test 4 days before my period was due and it turned up negative, DO NOT TRUST THOSE. My "PMS" was especially bad, I had every symptom you can think of, bloating, breakouts, severe mood swings, bad cramps, etc. I felt so ridiculously menstrual. I just thought it was a bad PMS cycle, because I have those ever so often. When I was 4 days LATE, I thought I might take a pregnancy test just to "be sure" even though I am late ever so often. And to be completely honest, I thought I was wasting the test because I knew I wasn't pg with these symptoms. Low and behold, (and to my utter shock) the test came back positive and so did 2 others and a clinical test.. and I am now 7 weeks pg.