Answer
(Fatwa: 275/154/D=1432)
(1) The custom of seventh month pregnancy ceremony (satvasa) is un-Islamic. We are asked to keep aloof from such customs.
(2) It is better to say sorry attending it.
Had you written the complete detail of the customs performed in this ceremony, we could have enlightened you in detail.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband