Testing time after implantation?

I believe I might have had implantation bleeding yesterday morning. It was bright pink when I wiped and today I just had a drop on some toilet paper and that's it so definitely no period yet. I'm 12 dpo today so af is due in 2 days. I was wondering when my HCG might be high enough to appear on a very sensitive test. My husband and I have been trying for 5 years, recently had a failed retrieval IVF cycle about 2 months ago. We haven't really tried since. I wanted a little break to heal. We were or are going to try another cycle once af comes. So I just want to know so i can fully prepare myself. I've been extra emotional recently, which is really my only different symptom from usual. The pregnancy tests i have are extra sensitive. I took one today, but it was negative. Any ideas?