Is it my period? ( I'm not pregnant I'm 17 )

Basically I didn't get my period so of December I spotted for 2 days and that was it. 2 days ago I went to the bathroom when there was a like a pinkish orange I guess discharge blood and the day after it was like a brownish color and it's very light like I don't even need to wear a pad or tampon and today there's a small piece of brown piece in the toilet paper but no blood like red blood I'm normally heavy but could this be due to the fact that I was late? I also was really stressed out and I stopped eating for about a week , this isn't pelvic inflammatory disease is it? I mean I went to the gynecologist in may and had a pap smear so I could make sure I didn't have BV or something and it came out negative so I dont understand why my flow is extremely light is this normal does anyone experience while their late ?