Irregular Bleeding on Birth Control?

I have been on an anti-candida diet for a week now. no sugar, no carbs, no yeast. just eating veggies and meat and in the morning yogurt. I have also been on birth control for almost a year now. I have never missed a pill, and take it at exactly the same time each day. I am sexually active, and a couple days ago my boyfriend and I had quite rough sex. as a extra precaution, my boyfriend never finishes inside me. I noticed a couple hours later light pink bleeding on toilet paper. later it became red blood and more of it. I went to my doctor the next day, and she felt my stomach for hardness (pregnancy) and my vaginal canal for irregularities. she found nothing with both tests, and advised I have a blood test for pregnancy and an ultrasound for uterine growths as a precaution. I seriously doubt I am pregnant; I have no pregnancy symptoms and this seems heavier then implantation bleeding could be. I want to know if its possible that My change in eating habits and/or the rough sex I had have any relation to the irregular bleeding I am having on the alesse 28 birth control pill?