pregnant or not?

Kara • 26 years old, married to my best friend and mommy to my sweet boy. ❤️
I am 18 dpo I had a somewhat period (very light) which ended three days ago. It's not like my normal periods so my husband keeps wanting to make sure I'm not pregnant. I took this today and inverted it to see because I kind of saw something. But I'm not sure how well I can trust the curved first response. Any ideas ladies?