Help! Is something wrong?

Victoria • 💗Mommy of 4 angels👼👼👼 and one little boy named Viktor and a little girl natalia! Pregnant with #3

I found out I was pregnant about 2 weeks ago, I've been continuing to take tests to see line progression. Today I woke up with severe cramps but no bleeding and I took a test and the lines have faded significantly! My first ultrasound is may 16th and then OB is June 7th, what should I do? Or should I not be worried. I'm only asking because I heard that the brighter the lines the higher hcg levels and they should double every 48 hours.