Hi, I'm 21 years old and I've had unprotected sex about 3.5 weeks ago, but I had my period a few days after intercourse. I've also been out of birth control for about 2 months now. Lately, I have been Cramping in my lower and upper abdominal, bloating, dizzy, nauseated, food aversions, etc.. Some symptoms similar to my when I'm on my period. But just a few days ago I found that my discharge had brownish redish color to it. I don't know if it's my period is starting because I have an irregular cycle. It's been 4 days now and my period still hasn't arrived. Is this something I should be concerned about? Is it normal? I have taken 3 pregnancy test and it all came out negative. Should I wait until after this month to see if my period comes to take a pregnancy test again?

At 4 days overdue it would likely be too early to test.

Wait another week or two, if you don't get your period then test again. If that test is negative wait until your next period is due. If you miss that one then test again, or see your doctor for a more accurate blood test.