PET scan mid-June...BFT this week...unknown date of LMP

taceituno

So, I have a history of Hodgkin's Lymphoma and had another PET scan on June 10th for my annual all-clear. I am clear, thankfully, but when I got my BFP this last Saturday, I realized I have no idea when my LMP was. My youngest is 16 mths and until recently was still nursing at bedtime. I never got regular with my cycles after her delivery. So, now I am freaking out about whether or not I was pregnant at the time of the PET scan. I will be going to a clinic tomorrow for a free limited ultrasound so I at least know how far along I am since I can't get in with a regular OB for a couple weeks. Has anyone had any experience with this?