Brown spotting 7 weeks + 5 days

(33) FTM here, pregnant for the first time ever through IVF and this evening I’ve just randomly had some dark brown spotting.

I haven’t had any spotting up until this point. Just some pretty intense nausea but still managing to eat.

I had a scan last week which showed a heart beat but baby was measuring a little on the small side.

I’m booked in to see a midwife on Monday and a follow-up scan with my clinic on Wednesday, could this wait til then or should I call up asap?

I’m a little panicked and would really appreciate some reassurance 🙏