Entitlement of statutory maternity benefit of a contract employee would be in operation up to the actual date of expiration of the contract only. It can not be a reason for the further extension of the tenure of the contract fixed earlier.
Coming to your case, it is discernible from your inputs, from 15-06-2018 to 06-06-2019, your total service comes to 356 days and it means that your contract of 89 days was already extended 3 times and on the EDD i.e., 19-05-2019, you are in the 3rd extended spell of your contract which ends on 06-06-2019.
Out of the total maternity benefit of 26 weeks' paid leave, you can avail of 8 weeks prior to the EDD and the remaining 18 weeks afterwards subject to the condition of the subsistence of the 3rd spell of the contract which expires on 06-06-2019. Therefore you can avail of the statutory maternity benefit upto 06-06-2019 only. I don't think that your employer will agree for a 4th extension so as to enable you to avail of the full benefit..
20th February 2019 From India, Salem