Conversion rate down drastically but lots of traffic

Hi everyone, our store www.the-bow-boutique.co.uk has in the last week drastically slowed down with conversions, we have been trading for many years now & steadily grown year on year. can anyone give any tips why we might be doing something wrong or slight tweeks we can make to improve conversions? we have email marketing which also seems to have slowed. it seems really odd all of a sudden as we havent made ant changes apart from verify the facebook pixel into our website. thanks