Implanon removal - TTC

Hi there everyone,
​I have recently had the contraceptive implant removed on 19 Dec in order to TTC. I didn't have periods whilst I had the Implanon. I had it removed once before and my periods returned within 1 months and we fairly regularly there after.
​We have been doing the deed every 2 or 3 days without fail since it's removal as we were told I would be fertile right away. I took ovulation tests regularly and always negative. Had some stabbing pains in my ovary / womb area 3rd Jan and then again on 8th jan. 
​Yesterday on 12th jan I had some spotting - not a lot just when I wiped which only lasted 12 hours. The pregnancy test albeit a really cheap one is negative.
​Any thoughts on what is going on? I am new to all of this!