Beta hcg negative. Chances of pregnancy?

Proper periods on June 3. First time Protected intercourse using condoms on June 11. Beta hcg on July 6, result was 0.63. Delayed and less periods on July 14 which was induced by taking primolut n. Upt was negative and beta hcg on July 16 was 0.244. Scan on July 20 showed cysts in ovaries and prescribed to take krimson 35. Again two beta hcg test on July 31 one result was 2.1 and another was 0.60. Why did I get 2 various results on the same day? And does 2.1 miu/ml indicates early pregnancy? But is taken only after 50 days of intercourse. And the periods on July 14 was very less and does primolut n reduce the flow? Inspite of negative results, why the periods was delayed? Am not sexually active after June 11. So is there any chances of pregnancy?