Worried about the last period. A gynac?

I think straight forward attitude will surely help me. So, the concern is, 1) My last mensis was delayed by almost 8-9 day's 2) Once I got my period the flow was not normal (if was on the heavier side) 3) The cramps were also more than mild. Can say was higher than usual (I have experienced the same pain only a few times before) 4) The flow decreased & so the pain in next in 2/3 days & gradually stopped on 6/7th day 5) I felt at one moment I've conceived but than I felt I'm not (as I'm not sexually active from from a couple of months) 6) I thought of taking a test at my place after a week as the information on the internet was driving me crazy. Guess what? It came -ve 7) I took one more test today & again it's negative. Now, I'm relaxed & don't feel an urge to visit a gynaecologist but still looking for some answers, 1) Should I get a ultrasound done? 2) I was on medicine (cough & all). If that the reason behind it? 3) Should I wait for next 2/3 weeks before visiting a gynac?