http://bonyg5gd2cszplkckqffzfcefig5jldgwt36gm2jqdaezlgs3nrfhjid.onion/bible/content/bible/cryptocurrencies/bitcoin/transactions_not_getting_confirmed/index.html
In general, the speed of confirmation depends on the fee you attach to your transaction; miners prioritize transaction that pay the highest fees.
Another reason could be that the Bitcoin network is overloaded at the moment. Sometimes a lot of unconfirmed transaction rack up (tens of thousands) these have to get processed, which will take a while.