Pregnant? Idk help please..

Hi, I've been burping a lot lately, my stomach has been feeling odd and I've been constipated (I know tmi yikes) but yeah. I was a week late on my period and had a light flow when I'm usually heavy, On the first day I had the worst cramps ever.I don't know if it's because of stress, my eating habits weight (I'm overweight) , or my anemia. Anyways after 6 days of light bleeding, I ate and now I'm burping a lot. I'm pretty worried since I guess it's a symptom of pregnancy? Unfortunately I have been only eating fast foods for the past two weeks, and I've been stressed as well because of school, family and friends and now because of my fear being pregnant. I just wanted to know if I'm okay. I have mentioned about this for the past few days on this app (TO whoever have read about this I'm sorry I'm on the feed again /: trouble with believing people). And like I'm just afraid. I'm going to take a pregnancy test tomorrow, however I never had sex but I've masturbated but unintentionally fingered myself with the hand that I touched my S/O's genitals (we were never naked, full clothing) I mean after five minutes I would go home and finger myself, never in front of him. So yeah I've been panicking for the past week over this since my period was a week late; then i had light bleeding for 6 days and now here I am. My stomach really hurts like a normal stomach ache; no I have not vomit, nor I don't feel like it. I've just been burping a lot and I was just wondering if I'm okay.. thank you