please help I'm only 20

Hi guys, so the first test is from Monday afternoon, second is from Tuesday mid day, third is from today (Wednesday) morning. Is there a progression? 
I went to the doctors yesterday ( Tuesday ) did a urine test and it came back negative, so they drew my blood and I should be getting the results back today or tomorrow. But after that I took a test (second picture) and it's clearly positive. Why did this happen? Am I pregnant? 
I'm really scared. I've been in a committed relationship for over 2 years and we know we're going to get married but I'm only 20, I plan on keeping this baby but I'm so so so scared. Any advice is welcome. We're in college so now he'll have to get a job, and advice on good paying jobs without a college degree? 
I'm scared to tell my parents. My brother is 25 and just got married this year and his wife got pregnant and is now 4 months pregnant. Due in October. If I'm pregnant I'll be due January.... I don't want to add this stress to my parents or disappoint them. I'm really scared....