what's going on with me lol

Claire
Hi I'm new to this please can somebody help me as I don't know what's going on with my body I had the implant taken out my arm on the 10th of January it had been in for 15 months I bleed for 4 days after it was taken out and then again 13 days later for just 3 days.
According to an app I ovaulated 6 days ago and all week I've had sore boobs, cramping, backache, a bit of feeling sick.
It's like one min I think I'm due to have another period so I wear a pad just in case next min I think something's not right I think I'm pregnant.
But on since trying since Jan I only get a faint line on ovaultion test and I use them everyday just to see if and when I am ovaulting and now 6 dpo I used a ovaultion test and just a really really faint line. 
I've had 3 kids before although there all teenagers now.
I'm now trying for another baby  below is my chart I track