What are the Virtues of the Day of Arafaah?

I am currently living in Canada for the purpose of study, but my permanent place of residence is between Jeddah and Amman. When I stayed in Amman during the summer break, I decided to go to Jeddah to deal with some official papers, and I intended to do ‘umrah if Allah made that possible for me and if I had a mahram and enough time to do ‘umrah. I intended to do ‘umrah from Jeddah because my mahram would be there. But because I was not certain that I would be able to do ‘umrah, on the day I travelled by plane I did not do ghusl, because I was menstruating and I had not yet decided to do ‘umrah. When I got there on the second day I did ghusl and formed the intention to do ‘umrah from Jeddah, and I did it.
My questions are:
Is my ihram from the miqaat of Jeddah considered valid or not?  Because of my family circumstances, we are always moving back and forth between Jeddah and Amman, and we always enter ihram from our house in Jeddah, even if we are on our way back from a trip to Amman and after staying in Jeddah for several days. We do not remember how many times we have done ‘umrah in this manner.
What is required of us if we should have entered ihram from the miqaat for the people of ash-Shaam (Greater Syria)? After I did ‘umrah I was uncertain as to whether I was completely clean following my period. If I think it most likely that I was still menstruating whilst I was doing ‘umrah, what is the ruling on my ‘umrah and what expiation do I have to offer?.