Light vaginal bleeding? Opinion please!?

Alright. Over the past couple of days I have had very light vaginal bleeding. At first I only noticed when I went to shower. And only because I saw light brown stains in my undies. For three days I noticed this, but I didn't notice or see anything coming out of me. Then, I guess on Saturday morning, I noticed myself bleeding very lightly. It's a very light brown color. I have no pain in my lower region, but my stomach has been slightly sore and since Saturday I have been constipated. I know very well this could be implantation bleeding, but I'm not sure because of the way it is spotting and the length of time. I know if it was an infection there would be an odor and there is none. I am very normal down there, it is just the light bleeding, or spotting. I live with my husband, and we frequently have intercourse. He likes to pull out which I know isn't a good way, but mostly he wears a condom. Last time we had intercourse which was yesterday, afterwards I went pee and I noticed that when I wiped there was pieces of dark brown tissue, but only then and I never saw it again. To my knowledge I am not pregnant, but it could be. My period just came on May 30th, and this is NOTHING like one of my periods, and my periods have never been in succession so closely. My periods in fact vary WIDELY, sometimes not coming for 5-6 weeks. I am 5'8 and 275 pounds, and I will be 22 on September 3rd. I was also investigating it maybe being a cyst but I would think this would have happened before. I am kind of worrying right now. Other then being constipated, for the past week and a half I have been finding the smell of my mint conditioner OVERWHELMING, which I find strange. I know that that's a symptom of pregnancy, but so early? My periods ALWAYS start off very very heavy and very very painfully. I know its not a period. I am unable to go to a doctor right now and I would really like some opinions. Thank you in advance.