I think its not a double spend.. blockchain will automatically inform you if your transaction is double spend.
upon checking the 2 transaction your fee is too low it will longer to receive by the receiver.. most of the fee these months is above 0.001 btc for miners fee. if you use electrum you can use the dynamic payment. Also you can relay in this site
https://bitcoinfees.21.co/ so that in the future you know what is the best miners fee..
For much better you can do not is to use this
https://www.viabtc.com/tools/txaccelerator/And maybe it can help to increase speed of your transaction
Use dynamic fees
So that you had a choice for fast to slow transaction speed..