If it is a chemical πŸ’”πŸ’”πŸ’”

My last period was the 1st of June, I had some brown spotting on the 1st of July it lasted for 3 & a half days no pain at all lots of discharge. 2 days ago I got 2 bfp then a negative this morning still lots of discharge but I'm worried it's a chemical I'm cycle day 42 now and this negative hpt this morning.
When would I expect to see heavy bleeding if I was having a chemical pregnancy?Β 
Now 10 days after suspected implantation bleed