Just an update, I tried checking the network propagation on blockchain and it says "No inventory information available"
Could it be the transaction is invalid?
IIRC, blockchain.info could not see the transaction in their peer's mempool and thus this would appear. It isn't a clear sign of it being dropped from the mempool since blockchain.info does not specifically connects to every node in the world.
I used to send zero-fee transactions all the time, but I gave up on this a few months ago. I had a 0.1 BTC transaction waiting for more than 2 weeks. In the end I Googled how to double spend it (with a fee) from bitcoin-qt core client. This was quite a challenge, but it did solve the problem.
How did you double spend it? I sent the transaction from blockchain phone app. You think it's possible to double spend?
Creating a replacement transaction would be relatively easy if the nodes are willing to relay your transaction to the miners or miners are willing to mine it for you. Majority of the network runs on the reference implementation which ignores any subsequent transactions spending the same input as any transaction in the mempool.
However, if majority of the network's mempool does not have your transaction, you can create another transaction spending the same output and they would relay it.
As a last resort, FSSRBF (First seen safe replace by fee) allows users to double spend without having much risks for the merchant. You need to extract your private key and go to coinb.in/#newTransaction and make a transaction fulfilling the criterias.
1. The outputs amount must be equal to or higher compared to the first transaction.
2. The outputs must be to the same address.
3. The fees must be higher than the first transaction.
After doing this, you can go to
https://coinb.in/#verify to check the transaction before going to
https://coinb.in/#sign, paste the raw unsigned TX and private key to sign. After you obtain the signed raw TX, go to
https://coinb.in/#broadcast to broadcast your TX.
