Can I Have An Implantation Bleeding Even Though I Had Negative Pregnancy Results?

Im 28 now and married for 7months. My husband has been unable to come during my fertile period because he is working outside. We want to have a baby soon as Im thinking of leaving the country soon. During December I had a long vacation and was with my husband. Before that I met a gynacologist and he prescribed me clomephene citrate for 5 days starting from my 2nd day of period. On 12 th day he asked me to get tvs done. From the tvs on 12th day, it revealed 2ova of good size. This gynacologist gave me an injection to release the ova and asked to do SI in 36hours.Also prescribed me Duphaston tds along with folic acid and calcium. Duphaston was prescribed for 3 weeks. My cycle is usually 25 to 28. Last period was in 7Dec. I have been having lower abdominal pain on and off with bk pains. For nearly 4 days Im having spotting. First they were very brownish. Now it has become a little reddish. Its often tissues that pass. But so much less than when having perids. Sometimes mucus also pass in brownish colour. Somedays i missed the duphaston pill on time and took
2pills together. I Did a urine pregnancy test and it was negative. What should I do? Is it my periods or implantation bleeding? Should I discontinue Duphaston? The 2 nd gynacologist asked to take it till 10th. My husband will be here this month. so I want to start clomiphene again? Am I pregnant?