Am I pregnant?

Hi everyone, I'm only knew to this sight I'm just looking abitta advice I have had the implant in since September last year my period was due last Monday I'm still waiting for it to make an appearance I have had loads of period cramps but no bleeding my partner is looking another baby our baby girl will be a year next month but personally I'm not ready I took a pregnancy test yesterday and it came up negative has anyone ever experienced this with the implant? Thank you for reading x