Tested pos for strep 7/2/17. Prescribed amoxicillin for 10 days. Twice a day. I would forget to take the 2nd pill at times. But never skipped a day. I had pills left over. Today is 11th day. I took one in the A.M. But I lost my pills. Am I at risk?

Strep. No, I think you have probably taken sufficient to eradicate the strep.
Possibly. Antibiotics MUST be taken exactly as directed to maintain tiger (level) in the bloodstream. Each time you missed a pill and the timer dropped the risk of bacteria blooming increased. If only part of the dose was taken because you stopped (lost) taking the pills, infection can come roaring back. Not taking antibiotics properly leads to resistant bacteria. Call your prescribing doctor now.
Strep. You should be fine but if you continue with sore throat, fever >100.4F, lymph node swelling, and dry cough I would recommend getting retested.