All Signs Point To Pregnancy But Positive I’m Not Pregnant! Please Help!!!?

Back in aug my periods started to come later and became lighter than usual. But every month I’ve gotten a period, it’s just always late. I ignored it and went on. Well around the time it started I started to get sick to my stomach a lot and sometimes start to gag. I just passed it off as it my terrible migraine giving me nausea. A few weeks passed and I started school again, buying new size 1 jeans. I started to crave Chinese food, pretzels, and Popsicles all the time! Like I had to have them every meal. So of course the size 1 jeans started to get a lil snug. After a few weeks I went to the doctor with my now barely fitting jeans and realized I’d gain about 5 pounds in just a short amount of time. So after that I started watching what I ate and still started to gain weight. My stomach started to stick out more and it’s recently started to look round like a baby bump. Also this week I started to feel flutters right below or around my belly button. I thought tht was weird and decide to do some research and all I got was pregnancy stuff. So I decided drink orange juice, something I’ve recently started craving, and after a short time it seemed like the flutters started fluttering like crazy. So this morning I got up around 4 a.m. and had some very very light bleeding. And as the day went on it never got heavier until 30 min. ago. But it looks like old blood and it’s a dark red not a bright red. I don’t know what could be going on, because everytime I look something up it always brings me to pregnancy and I know I’m not pregnant cuz I’m still getting periods every month. Do u have any idea what this could be?? Shuld I go to the doctor?? Any advice wuld rele help me out!! Thanks in advance!