Pains and spotting

Sharni • 3 angels babies LGH2015 , LEH2019, LFH2020 1 rainbow EPH2016 Carriers of short rib polydactyl syndrome type 3. Will be starting our IVF with PGT journey next year
Ok so silly question but my period was a day late this month the day it was due I had brown spotting so knew it wa comming 
​Got AF the next day and had a medium flow for two days 
​My period ended 3 days ago 
​However today I have had sevre lower cramps where I could not move 
​And started spotting again today 
​Still have cramps but more of a shorting pain on my left side 
​Has any one ever experienced this as this is a first for me 
​Regards