Frontal shedding

[Yoespero]

I've been using regaine for the past few weeks now and although I haven't noticed a great amount of hairs falling out in the shower (about 10-20 every wash) I have noticed my hairline receding a lot further , in a horse shoe shape, with thinning as far back as the crown area. I have been applying the regaine in thinning areas further back past the hairline and was wondering if this is a normal shed prior to regrowth,

Thanks in advance