Why am I still getting a faint line on my blue pregnant test?

Aleah

I’m 20 years old now almost 2 months late. I get my period of the sixth of every month. I’m never late. And I’m not on birth control, and also I had unprotected sex in May, and June. I didn’t have my period in July, or August 6. I’m having light abdominal pain, back pain, morning sickness without vomiting, constipation, diarrhea, and my nipples are crusting.