I believe the current recommendation is for pregnant women, especially those with heart conditions, to self-isolate - but as you can't reach your specialist, the next best source of advice would be your GP. Most GP surgeries are operating on a telephone and video chat system so you should be able to speak with either your GP or the duty GP without any undue delay.
Next best after that might be telephoning to the BHF Heart Helpline cardiac nurses on:
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