Starting a family advice.

My so and me are trying to convince. I had my contraceptive implant removed on Dec 1st. When I was on the bc I didn't have periods at all so I'm struggling to understand if my cycle is back to norm or if I could be pregnant now. I had some spotting after the implant came out and what seemed like a normal period between 20th and 24th. I have such tender breast but don't know if it's too soon to test? I heard you should test a day after your period is due, mine would be due on the 17th of Jan if my cycle is "regular". Any advice much appreciated.