Pregnancy cramps

Hi everyone. I'm currently 4 weeks 3 days pregnant. I visited a gynae 3 days back as I was spotting and having very bad menses like cramp. My spotting has since stopped, but the cramps are persistent, just on my left side. Occasionally feels like something stabbing me, but very bearable. Hcg on 4 weeks was 479. No sac visible in scan, but I understand it might have been too tiny. Should I see a gynae again or wait out till 6 weeks? Concerned about ectopic pregnancy... Thanks all.