On pill, tests negative and regular periods. Can i be pregnant?

Patient: Hi,I am 30 year old female taking diane-35 for past 5 months for my PCOS problem and having regular periods. On 30th July, I had unprotected sex and next morning i took an emergency contraceptive also. After two weeks, on 13th Aug, i got my usual period of 5 days. I was somehow freaking out to confirm that i am not pregnant.I got a quantitative beta hcg test done on 24th Aug and then on 31 Aug. The level was less than 1.2 both the times(as per the lab results). I got my next expected period on time (on 10th Sept, which was pretty light on first 2 days, may be because of emergency contraceptive, not sure though).Again, still confused, as i was feeling some discomfort in pelvic area, I took a Home pregnany test on 15th sept which came out negative.This pelvic discomfort is really making me think all the time as i have read different stories on the internet regarding all negative tests and still pregnant.Please help me getting some peace of mind.