Implanon/explaining removal

Hi everyone! First time posting! I had my implanon removed 18 days ago. Before then, the previous 3-4 months my period kept trying to come despite not having it for the previous 2 years at all while on the implant. I assumed as soon as it came out I would be bleeding within days. But I’m still yet to have any bleeding at all. The first week it came out I had consistent cramping but nothing else. The last two days I have had nausea coming and going, sensitivity to smells and I swear my breasts have almost doubled in size. I took a pregnancy test this morning with FMU and it was negative. What do I do from this point? If my period still doesn’t show its face how do I know when to test again? And is it possible I could already be pregnant? With my first baby I fell pregnant 5 days after stopping the oral contraceptive! Thank you so much!