Could I Still Be Pregnant Despite A Negative Home Test And A Late Period When Prescribed Gynecoside Tablets?

Hey there! My periods are 1 week late this never happens before. Its been one year and 3 months to my marriage. I took strip test at home but it was negative. Yesterday i went to tha dr. She took my ultrasound didnt tell me anything but prescribe me this gyenocside tablet to take i took 2 tablets at night but still dont have my periods. I want to ask is there any chance of pregnancy ? I want to conceive. Should i go for lab test ??