thanks for sharing your question. Such questions require analysis of horoscopes of both male and female. For your chart, your 5th lord is moon placed in Pisces rashi and in nakshatra of Mercury with Venus as sublord. Moon is placed in 12th house in Chalit making it weak and also your 5th house is aspected by Saturn from 8th house thereby causing delay. Position of Venus in aries along with Sun is not good as well from semen pov.
I highly advice seeking medical counsel for you and your wife as science can today help massively (astrology cannot replace medical help)
Below are good periods for child birth wish fulfillment/conception
* Venus-Mercury-Mercury: 9/11/2018 to 4/4/2019 as Mercury is placed in nakshatra of Ketu but has Moon as sublord
* Ven-Mercury-Moon: 14/1/2020 to 9/4/2020
* Ven-Mercury-Rahu: 9/6/2020 to 11/11/2020
Chanting mantra of moon and wearing pearl will help.