Sales suddenly stop

So me and the wife just started our first listing.. We started slow with 2 sold the first two weeks then we kinda had a gradual rise from 1-3 to 2-4 to 5-7 units a day for the last 3 weeks. It seemed as if sales were gradually gonna rise as more time passed as we were using ppc. We are only 150 units from being empty of inventory. Thursday we dropped form 7 units sold to 4.. Friday we only sold 2 and now it’s afternoon on Saturday and we have 0 sales.. ppc is still the same as it was and our bsr has dropped about 20,000 due to the sales dropping we were once wondering what we was gonna do if we sold out too fast to now wondering if we are being suppressed of some sort.. is there any reason why or how this happens with no changes to keywords, ppc or photos? This is weird.. going from a sharp increase to all of a sudden not selling anything or just sitting on an order or 2 for hours on end. Any help/advice would be