Stimming and spotting?

I started having brown spotting stim day 5, which was Friday afternoon. It has continued through today. I called the clinic Friday afternoon and they didn't seem concerned because its brown, but I'm still worried because I havent had this before and we are hoping to be able to do a fresh transfer this cycle. Has anyone else experienced brown spotting before during stims?

My lining was at 5 on Monday and still at 5 on Friday so I am hoping since its brown I just had some bleeding early in the week thats working its way down now and my lining will build itself up maybe? My next appointment is Monday morning.