Progesterone only pill and bleeding

[CM0301]

I started to take the POP approx 5-6 weeks ago. First month was over the counter Hana version, then got prescription (which is Zelleta). First month was absolutely fine. Had period on Hana and started taking the Zelleta towards the end of the period. I am still bleeding from the period which started 11 days ago. I thought it was just usual period tail off but it hasn't stopped and now it seems to be increasing from spotting to bleeding. I don't know what to do. Should I persevere, but I really don't want to keep bleeding; stop altogether now mid packet; go and buy the over the counter version and swap mid packet to see if that is better; or ?? I am at a loss but I really dont like this. Thanks if you've read this far.