Trigger warning. Possible miscarriage.

How would I know if I was miscarrying if I am not sure I was pregnant? Is there any way to be sure without seeing a dr? I'd rather not do that if I don't have to... Last month my period was really short and light which was weird for me. 3 days of barely spotting. I have been not feeling well and sore breasts I even threw up yesterday. I am having a really Heavy painful period this time. I passed something really weird this morning. I posted it in the period section and a few people confirmed what I was worried about and suggested a possible miscarriage. If I need to see a dr I will, but I have anxiety issues and really don't like going to the dr. Any help would be appreciated. Thanks