Pregnancy test

Hi this is my first pregnancy and I'm super paranoid and scared of miscarrying. I have a 6 weeks appt thurs and 8 weeks ultrasound the 20 but I keep testing do you think I could stil be pregnant I haven't had severe cramping or bleeding I'm just so nervous everyday haven't had much symptoms in the beginning when I found out I had a few but other than being really tired and exhausted nothing. These test are from today in about 5/6 weeks and the Walmart .88 ones aren't seem to get much darker than this for me if anyone can help thank you have put me at alittle less worried