BFP then BFN the next day :-( Anyone experienced this?

[SusieS2019]

I've not posted before, just looking to see if anyone else has experienced anything similar.
I've had a CP and a miscarriage at nearly 7 weeks and we are ttc again. I'm tracking ovulation and was 9dpo yesterday.
I have lots of symptoms- sore boobs, creamy cm, bloated and gassy etc.
I tested with a frer yesterday and think I got BFP- the line was faint but pink and came up within the time frame.
However, this morning, with fmu I tested again with frer and got bfn.
Any ideas?

It could be that there wasn’t enough HCG in FMU (I get better results with a 4 hour hold in the day) or it could unfortunately be another CP xx

9DPO is vey early.. as is 10DPO. Just hang on until the day before your period is due.

Before these super early tests, most woman would never have known they were having a chemical pregnancy.. they seem to cause an awful lot of worry & heartache

Do you have a pic of the test? I know there has been a few problems with FRER on here before already having indent lines x