I have a regular 30 days cycle period.my last period is last jun 3, i took Gonal-F injection for fertilzation,?

I have a regular 30 days cycle period.my last period is last jun 3, i took Gonal-F injection for fertilzation,between jun 4-15,we got intercourse jun 15-19 straight, then i got a very light spotting last jun 22 & 23, and a bleeding jun 24-26 but not that heavy and my abdomen is not aching unlike period and and this is not normal to me..Is it a menstruation?or implantation bleeding?i got also backaches..is it possible that i am pregnant?and can i take now urine pregnancy test?