Oo naman pwede, pero better if you go to your OB muna and let your dentist know na 4 months pregnant ka para ma-adjust nila ang approach, usually safe ang dental work during pregnancy especially kung may pain na, pero they might prefer to do it during second trimester like now mo pa lang. Best talaga na i-confirm with your doctor kung okay lang for your specific situation, kasi bawat pregnancy ay may sariling considerations.