ladies I need help. I know i posted a picture yesterday of the pregnancy test that came out positive but when I first…

ladies I need help. I know i posted a picture yesterday of the pregnancy test that came out positive but when I first took it, it showed up negative. The second line didn't pop up till after like 20-30 min .... can I still be pregnant? I made a doctors appointment but i have to wait 2 weeks :( has anyone ever gone threw this?