Possibly pregnant ?

I’m currently 8 or 9 days late for my period. I took a test at about 2 or 3 days late and it was negative. But I still have yet to get my period. I asked my friend and what not. And she said the same thing happened to her. She took one about 5 days after her missed period and it was negative and then again about 15 days after her missed period but this time it was positive. (She is now almost ten weeks, so excited for her) but the question is could I possibly be pregnant myself. Yes I had unprotected sex, Several times over my ovulation period. but I don’t get it. Why would I be getting a negative if It wasn’t truly negative. Since the unprotected sex I’ve had some weird symptoms happen. But they could all be regarding a period coming. For example, my nipples itch and tingle constantly. The water in the shower that normally feels really good to me feels like it’s burning my skin now. I feel very tight in my uterus area. My period still isn’t here. I’ve been breaking out pretty bad. And my sweet tooth is extremely bad this last couple week or two. What do you guys think, please let me know!! I’m terrified. I will also add a picture of my cycle chart.