What Causes Bloating After Taking Birth Control Pills?

Hello, my name is Sarah. I m just a little freaked out here about the birth control I m taking, and I just needed some professional advice. I m 18 years old and have been on loestrin 1.5/30 (28) for about 4 months now, and before that I was on Alesse for a few months but it gave me irregular periods. Now I reason I m emailing you is because I ve been noticing some signs that occur during pregnancy, but I have not had intercourse without protection. How possible is it to get pregnant when you are in contact with pre ejaculate? I was never penetrated however. The symptoms I have been having are things like bloating (however I do get bloated easily, and I ve had trouble with bowel movements for aslong as I can remember), I have veins on my breasts, I have one on my upper thigh, I can t tell if my areoles have gotten darker (they have been more defined around the edges though) and I ve been very gassy. Not to mention I ve had no periods since I ve been on it, but I ve read that women on it don t usually get one. I m just kinda freaked out, and I really needed to ask someone. Thank you!