Thank you for reaching out.

Unfortunately a hefsek performed 30 minutes after sunset is too late to count. If you have the earlier hefsek, we strongly recommend that you bring it to a halachic authority for evaluation explaining the urgency of the situation. A hefsek need not be completely clear to be valid and many shades of brown are acceptable.  If the earlier hefsek is deemed acceptable you may immerse as scheduled Tuesday night. 

In extreme cases there may be room to permit immersion during the daytime of the 7th day; however, that is conditional on not seeing your husband until after nightfall. So even if theoretically you were to immerse Wednesday morning, it would not help the situation as you would not be permitted to see your husband afterwards. 

We understand this is a very challenging and frustrating situation, dealing with miluim, war, sirens, and a baby on your own. We wish you much strength in getting through this difficult situation and may Hashem bless and protect you and your whole family.

Please feel free to get back to us with any further questions.

Bsorot tovot!