Pregnancy Scare. Please help! :(

So I'm 16 and I'm having a bad scare. This is going to sound dumb, trust me, but I can't help it. So basically like 3-4 weeks ago I put my hand deep down there. Before that I wet my hands and cleaned them swiftly with a bathroom rag. Since like two weeks ago I've been having many symptoms of "it" which freak me out. I've never had intercourse or been with a guy like that, so yeah I know it sounds dumb but I can't shake the feelings. I got my "period" like 9 days ago and I put it in quotation marks because it was very light and on and off. On like the third day (it lasted 4-5 days) it was a little bit heavier but then at the end of that day it was light again. Usually my period are pretty long like 5-7 days and heavy. So that really freaked me out and I feel like it might be spotting. I still have brown discharge and like colored stains to my underwear even though it's been about four days since it ended. Symptoms-wise, I'm getting many headaches, stomach aches, intense back pain, nausea, moodiness, emotional-ness, frequent urination and boob swelling. My boobs have gotten bigger which is normal during my period but not after so it is scaring me since it isn't a symptom for much other stuff. I've told my mom about my sickness but I haven't mentioned the P word. I went to the doctor like last week for symptoms and he didn't do much. I basically told him I felt sick and the stuff but he said it was probably stress since I just started school. I've had scares before and some symptoms were cuz of stress but this one feels different because of the period thing and the boobs and back pain. I know it's dumb, but I feel like maybe someone did "something" in my house and some of it went on the rag I used to clean my fingers or if somehow some got in "there" but idk. Another thing scaring me is that I took a homemade test with baking soda and peed in it, and it fizzled. When it's negative it shouldn't apparently. This was like one or two days before the "period." I'm really hoping I somehow did it wrong or maybe I read it wrong but yea. It's a big factor in why I'm worried. Sorry it's so long but I'm really worried and stressed out by it. I've lost my appetite a lot too. I hope this information helps and you can explain reasons why I might have all these symptoms or why it's happening. Also why I have these symptoms after my period ended. Again, I know it's dumb, but I'm a very worrisome person and would appreciate kind and helpful answers. Thank you.